Hi all - there might be a better place to ask this, if so please suggest where.

The plastics processing toolbox has a great variety of data on material properties, but there's no indication in the software about where this data came from. Specifically, I'm working with the viscosity-shear rate-temperature data for ABS and would like to know that there's a reputable source behind the numbers. Does each manufacturer provide the data for their polymer, or is it a different source? Also, how exactly is the "generic" data curve generated?

Thanks in advance.