Bayer Material Science puts out the exact same guide (with their name on it) but you need to register on their site to get it.
A second guide by Bayer expands on the concepts behind snap fits for plastics.
http://fab.cba.mit.edu/classes/S62.12/people/vernelle.noel/Plastic_Snap_fit_design.pdf
A better, in my opinion, snap fit guide is circulated by BASF:
http://www2.basf.us//PLASTICSWEB/displayanyfile?id=0901a5e1801499d5
It has a corresponding snap fit calculator: http://www2.basf.us/businesses/plasticportal/pp_techRes_tools_snapfit_en.html
BASF also has a good molding guide:
Design Solutions/General Molding Guidelines: http://www2.basf.us//PLASTICSWEB/displayanyfile?id=0901a5e1801499d2
and a cost calculator:
http://www2.basf.us/businesses/plasticportal/pp_techRes_tools_costcalc_en.html