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<HTML> <HEAD> <TITLE>SAO/NASA ADS HELP: Direct Access</TITLE> </HEAD> <BODY BGCOLOR="#ffffff"> <A NAME=top></A> <CENTER> <TABLE CELLPADDING=0 CELLSPACING=0 WIDTH=90% BORDER=0> <TR> <TD COLSPAN=2 VALIGN=bottom> <IMG SRC=images/adslogo.gif WIDTH=150 ALIGN=bottom> </TD> </TR> <TR> <TD COLSPAN=2 ALIGN=left VALIGN=bottom> <A HREF=http://cdsads.u-strasbg.fr/>SAO/NASA ADS</A> -> <A HREF=index.html>Help</A> -> Direct Access </TD> </TR> <TR> <TD BGCOLOR="#ccccfc" COLSPAN=2><IMG SRC=images/dot.gif WIDTH=15 HEIGHT=1></TD> </TR> <TR> <TD VALIGN=top> SAO/NASA ADS Help Pages </TD> <TD ALIGN=right VALIGN=bottom> <a href=feedback.html><img src=images/left.gif border=0>Prev</a> | <a href=proc_descr.html>Next<img src=images/right.gif border=0></a> </TD> </TR> <TR> <TD COLSPAN=2> <UL> <A NAME=Direct_Access_to_ADS_Data_Holdings></A> 6.3 - Direct Access to ADS Data Holdings <A NAME=bibverify></A> <A NAME=Generating_and_Verifying_Bibcodes></A> 6.3.1 - Generating and Verifying Bibcodes The bibcodes (see <A HREF="data.html#bibcodes">Bibcodes</A>) required for direct linking to ADS data can easily be built from a regular reference in a paper. For instance the reference: <DL> <DT><DD>Rester, C. et. al, 1989, ApJ, 342, L71 </DL> translates into the bibcode 1989ApJ...342L..71R To verify that a bibcode is correct, you can use the <A HREF="http://cdsads.u-strasbg.fr/verify.html">Bibcode Verification Utility</A> It is a simple interface allowing you to determine if a bibcode exists in the ADS and what other information is available for that bibcode. Checking the bibcode generated above with the Bibcode Verification Utility results in: <PRE> ADS Astronomy Database Bibcode Verification YES, 1989ApJ...342L..71R is a valid bibcode Abstract available SIMBAD Objects available NED Objects available References available Citations available </PRE> This indicates that the abstract is available through the ADS, together with other links. Note that if the bibliographic code contains an ampersand (&), it should be escaped with the html sequence "%26" in order to be properly translated. While this is not necessary with all browsers, it is certainly a good idea. To automate the generation of bibcodes from references we provide a <A HREF="http://cdsads.u-strasbg.fr/pubs/resolver/">Bibliographic Reference Resolver</A> The Reference Resolver allows users and information providers to query the ADS databases to verify the existence and availability of a particular bibliographic reference. The resolver attempts to be as flexible as possible in parsing reference strings and identifying the respective records, so that different citation formats are supported. This resolver can be used either through a webform or as a script. <A NAME=Abstract_Links></A> 6.3.2 - Abstract Links The URL abs is available for users to directly access full records in the ADS Abstract Service by bibliographic code (see Building Bibcodes above). abs may be used to link directly to our abstracts from outside of the Abstract Service. For example, authors may wish to use this on home pages, curriculum vitae, or on-line reprints. abs queries the datasets for the requested record. Full journal information, including abstract, authors, keywords, etc. is returned for the bibliographic code if it is in the system. If there is no entry in the database specified for the entered bibliographic code, an error message is returned. The URL for such links is: <DL> <DT><DD> http://cdsads.u-strasbg.fr/abs/bibcode </DL> where bibcode represents the unique bibliographic code identifier for the paper in question. This technique can be used to provide links to the ADS from HTML documents which include lists of references, such as: <DL> <DT><DD>Rester, C., et al., ApJ, 342, L71 [ <A HREF="http://cdsads.u-strasbg.fr/abs/1989ApJ...342L..71R">ADS Abstract</A> ] </DL> Linking to online ADS records rather than creating your own pages containing bibliographic information downloaded from the ADS ensures that you will always get the most up-to-date information for the records in question, including links to relevant resources such as data tables, astronomical object databases, reference and citation links, etc. Similarly, the URL doi is avaliable for users to directly link to full records by DOI (Digital Object Identifier). The URL for such links is: <DL> <DT><DD> http://cdsads.u-strasbg.fr/doi/DOI </DL> where DOI represents the unique identifier, assigned by the publisher. For instance the above link using DOI is: <DL> <DT><DD>Rester, C., et al., ApJ, 342, L71 [ <A HREF="http://cdsads.u-strasbg.fr/doi/10.1086/185487">ADS Abstract</A> ] </DL> <A NAME=Scanned_Article_Links></A> 6.3.3 - Scanned Article Links Links are available for users to directly access scanned articles from the ADS Scanned Literature by bibliographic code (see Building Bibcodes above). These links may be used to link directly to our scanned articles from outside of the Abstract Service. For example, authors may wish to use this on home pages, curriculum vitae, or on-line reprints. The first page of the article is returned with links for printing the article. If there is no scanned article in the database for the entered bibliographic code, an error message is returned. The URL for such links is: <DL> <DT><DD> http://cdsads.u-strasbg.fr/full/bibcode </DL> It requires a bibliographic code as an argument. <A NAME=Embedded_Queries></A> 6.3.4 - Embedded Queries This section describes how the abstract service can be accessed from embedded forms. The URL for submitting embedded forms is: <DL> <DT><DD> http://cdsads.u-strasbg.fr/cgi-bin/abs_connect </DL> The syntax is: <DL> <DT><DD><a href=http://cdsads.u-strasbg.fr/cgi-bin/abs_connect?param1=val1&param2=val2&... >...</a> </DL> where parami are the names of the parameters and vali are their values. There are no spaces allowed in a URL. Any blanks need to be encoded as a '+' (e.g. between author last and first names). The <A HREF="http://ads.harvard.edu/cgi-bin/get_field_names.pl">list of the possible parameters</A> and their possible values is available to build queries. It is advisable to use only the more basic parameters for such queries since the more complicated parameters are more likely to change with future versions of the search system. One use of this is for including a link to the bibliography for a particular author in a document. To do so, use the following syntax: <DL> <DT><DD> http://cdsads.u-strasbg.fr/cgi-bin/abs_connect?author=last,+f.&return_req=no_params </DL> This sets the author=last, f, and prevents the listing of parameters at the bottom of the page (return_req=no_params). If you want to specify the author middle initial in addition to the first initial, use exact author matching (&aut_xct=YES). To build a search for two different formats of author names, enter the two author arguments separated with a semicolon. <DL> <DT><DD> http://cdsads.u-strasbg.fr/cgi-bin/abs_connect?author=last,+f.m.;last,+first+m.&aut_xct=YES&return_req=no_params </DL> Such a link will always provide access to the latest bibliography of an author without the need to update anything. Sometimes such a list includes articles by somebody else with the same name. You can exclude specific articles from the results list with the command <DL> <DT><DD>exclude=bibcode1,bibcode2,... </DL> You can also include specific articles with the command <DL> <DT><DD>include=bibcode1,bibcode2,... </DL> This allows for finely customized bibliographies. <A NAME=Perl_Script_Access></A> 6.3.5 - Perl Script Access There are two PERL libraries currently available which provide direct access to the ADS search engine through a suite of PERL functions and scripts. The reccommended library, which is available as a PERL 5 module, is <A HREF="http://search.cpan.org/search?dist=Astro-ADS">Astro::ADS</A>, written and maintained by Alasdair Allan. An older library, which was originally written for PERL 4 but which does work for later versions is <A HREF="http://ads.harvard.edu/www/adswww-lib/">also available</A>. <A NAME=Z39.50_Access></A> 6.3.6 - Z39.50 Access The ADS can be accessed through a <A HREF="http://cdsads.u-strasbg.fr/abs_doc/ads_server.html">Z39.50 interface</A>. The <A HREF="http://lcweb.loc.gov/z3950/">Z39.50 protocol</A> is well-known and used by library systems and software. </UL> </TD> </TR> <TR> <TD BGCOLOR="#a0e0e0" COLSPAN=2><IMG SRC=images/dot.gif WIDTH=10 HEIGHT=2></TD> </TR> <TR> <TD COLSPAN=2 ALIGN=right> <A HREF="#top"><IMG BORDER=0 SRC=images/goup.gif> Top</A> | <a href=proc_descr.html>Next<img src=images/right.gif border=0></a> </TD> </TR> </TABLE> </CENTER> </BODY> </HTML>