Certain MSU-hosted archive URLs may be restricted to legacy database members.
URLDate
Verified		Extra Software
Requirements
(if any)		Access
Conditions		Notes
http://ssrc.psu.edu/pdf/hardness_traction_baseball.pdf05/26/2010PDF ReaderHosted on Center for Sports Surface Research website
https://archive.lib.msu.edu/tic/its/articles/2009j[...] 10/18/2011 PDF Reader