1.

Technical Paper
Technical Paper
1. Gasoline Engine Oil Specifications, Past, Present and Global.
Johnson, E.R. ; Olrele, R.M. ; McMillan, M.L. ; Clark, S.L.
Pub. info.: 2009 SAE Powertrains, Fuels & Lubricants Meeting : technical paper.  2009.  Warrendale, Penn..  Society of Automotive Engineers
Title of ser.: Society of Automotive Engineers technical paper series
Ser. no.: 2009
2.

Technical Paper
Technical Paper
2. A Study of the Response of Nonlinear Springs : Final Report
Hyer, M.W. ; Knott, T.W. ; Johnson, E.R.
Pub. info.: NASA Technical Reports.  (NASA-CR-188602),  pp.1-126,  1991.  National Aeronautics and Space Adminstration