Configuring Elsevier ScienceDirect Resource Links

Elsevier ScienceDirect uses an algorithm known as MD5 Digest to verify the security of incoming search queries. This algorithm is generated automatically by WebBridge when the linking URL for a Resource Definition is correctly configured using special system-generated field selectors. You do not need to create or modify these field selectors but you must verify that they are correctly placed in the URL.

The following link can be used to provide article-level linking to ScienceDirect:

http://www.sciencedirect.com/science?#@BEGMD5#_ob=GatewayURL
&_origin=WEBBRIDGE&_method=citationSearch
&_refkey=#@AULAST###@YEAR###@SPAGE#&_volkey=#@ISSN###@VOLUME###@SPAGE#
&_version=#@ELSEVIERSALTVER##@ELSEVIERSALT##@ENDMD5#_ob=GatewayURL
&_origin=WEBBRIDGE&_method=citationSearch&_refkey=#@AULAST###@YEAR###@SPAGE#
&_volkey=#@ISSN###@VOLUME###@SPAGE#&_version=#@ELSEVIERSALTVER#&md5=#@MD5DIGEST#

WebBridge calculates the MD5 Digest on the query information enclosed by the #@BEGMD5# and #@ENDMD5# field selectors and includes the MD5 Digest in the final URL. Note that this method requires some information in the URL to be repeated after the #@ENDMD5# field selector so that it will appear in the final URL.

This URL can be expanded to include optional elements. If you add optional elements or if Elsevier requires a change to this syntax, review the following:

• Special Field Selectors
• Elsevier Linking Methods

Special Field Selectors

WebBridge uses the following field selectors to define a portion of the URL as the OpenURL query string:

Field Selector	Function
#@BEGMD5# and #@ENDMD5#	These field selectors are used to mark the query portion of the URL for which to calculate the MD5 Digest. Note that everything in between these field selectors is dropped from the final URL.
#@ELSEVIERSALTVER# and #@ELSEVIERSALT#	These mandatory field selectors are required for calculation of the MD5 Digest.
#@MD5DIGEST#	Ths field selector is replaced by the calculated MD5 Digest.

If you need to deviate from the URL example, you must duplicate any changes that you make between the #@BEGMD5# and #@ENDMD5# field selectors and put them in the portion of the URL after the #@ENDMD5# field selector that is used to create the final link.

Elsevier Linking Methods

Elsevier provides three different means of linking (linking keys) to their articles: volkey, refkey, and piikey.

You can form the volkey and refkey methods from common OpenURL elements. The piikey method is a reference number that some external Origins may provide.

You can use field selectors to reference specific citation information to use with Elsevier's volkey and refkey linking keys.

Linking Key	Mandatory citation information	Including optional citation information
volkey	ISSN#Volume#FirstPage	ISSN#Volume#FirstPage#Issue#
refkey	LastName#Year#FirstPage	LastName#Year#FirstPage#LastPage#AuthorFirstInitial

If ScienceDirect receives more than one linking key, then it will create an OR search out of them. In the example link above, the refkey and volkey are defined using field selectors as follows:

&_refkey=#@AULAST###@YEAR###@SPAGE#&_volkey=#@ISSN###@VOLUME###@SPAGE#

When Elsevier receives this link, it performs an OR search against its database using the refkey value and the volkey value.

All OpenURL queries to Elsevier through WebBridge must contain the following additional element as specified in the example URL, above:

_ob=GatewayURL&_origin=WEBBRIDGE&_method=citationSearch