Source Publication (e.g., journal title)
COMMON WISDOM says that currency is what is valued in online databases. With the exception of genealogists and historians, it is assumed that readers don't want old materials. From the publisher's side, it just isn't cost effective to convert older bibliographic or full-text articles to digital form. For those who want older material, print--at least until recently--was thought to be the medium of choice.
This common wisdom is being proved not so wise, as readers are accessing both new and older information when it is available online, and publishers are rushing to digitize long runs of magazine and journal articles and the indexing tools that point to them.
Tenopir, Carol, "Oldies But Goodies" (2002). School of Information Sciences -- Faculty Publications and Other Works.