Thanks Green, I hope you can crack it.
The SAE has another one I'd like to read: B. Cockbill and J. Bennett, Ford Motor Co., “The Effects of Crankcase Oil Viscosity on Engine Friction At Low Temperatures,” SAE 2000-01-2052
They are both behind paywalls. Its been 12+ years since I was taking some tertiary classes and had LexisNexis access but at that time there was nothing I wanted that I couldn't pull out of it. We had the same privileges as the professors did even back as an undergrad.
The two are both cited by ZDDP Plus but in what look to me to be an ambiguous/dubious way for marketing.