Sources used since 2/1

Since Mr. Creagan recommended to me that I do a blog post of all the sources I've had so far for my research, this is my blog post for them. I had almost 30 sources before I started this project; these are just the sources I've used since I started the project and I haven't had to use much outside of my initial research.
All of my sources so far:

http://findarticles.com/p/articles/mi_m0HFI/is_3_54/ai_100463197/
For when putter grooves were first used and CNC machining putters

http://www.gelputter.com/
Different kinds of putter faces

http://www.andrewricegolf.com/tag/putter-weight/
How much putters usually weigh

http://www.franklygolf.com/gripsizeandputterweight.aspx
Another source on the weight of putters

http://csquaredgolf.com/tag/putter-head-rotation/
General swing path of a putter

http://puttingzone.com/MyTips/lengthlie.html
Very useful site for putter shafts, including lengths, lie of the shaft to the ground, etc.

http://puttertalk.com/community/index.php?topic=25054.0
This was very helpful in determining how wide the putter shaft is

http://golf.about.com/od/faqs/f/shaft_weight.htm
Good for figuring out how much heavier my shaft was compared to metal ones

http://www.cnczone.com/forums/general_metal_working_machines/20588-what_coolant_do_you_use.html
Different kinds of coolant