http://tags.library.upenn.edu/tag/transportation+article_search_engines PennTags Feed http://tags.library.upenn.edu/makerecord/url/2271 http://tags.library.upenn.edu/makerecord/url/2271 Bibliographic citations for materials received at the Transportation Library, Northwestern University, since 1976. http://tags.library.upenn.edu/makerecord/url/2268 http://tags.library.upenn.edu/makerecord/url/2268 TRIS Online provides access to almost 450,000 records of published transportation research through a searchable database. Over 470 serial publications are regularly indexed and abstracted for the database. TRIS Online includes material indexed and abstracted by TRB as well as the material entered by the Transportation Libraries at the University of California at Berkeley and Northwestern University.