Does anyone have access or a pointer to the origin for the Fong statistical test used in Kano scoring? Lots of websites reference it as "the thing" to use when evaluating Kano surveys, and I found a bunch of academic papers referencing it second hand, but the apparently original paper "Using the Self-Stated Importance Questionnaire to Interpret Kano Questionnaire Results" that seems to have been published in 1996 evades my online searching skills. I'm not looking for a pirated copy, happy to buy it from the publisher, but it seems to have fallen into a black hole. Searching for the paper just returns a ton of secondary references, that quote it.

The reason why I'm looking for it is that the formula looks like a two-proportion z-test that should work if the two samples are independent, but Kano scores are from the same population, so if I understand this whole thing correctly, the main test that the web and the academia copies and pastes doesn't really apply.

I'd love to peek into the original paper and understand what it was based on and why. If you know where I could find a copy, or maybe have one handy to check what Fong actually wrote about it, I'd appreciate a pointer very much.