Author-hosted notes: math.berkeley.edu/~alanw/GofQ.pdf
Appendix A, pages 119–121 in the displayed text (PDF pages 119–121): fractional densities, their product and integration, and the intrinsic Hilbert space obtained by completing compactly supported half-densities. The preface identifies courses in 1992 and 1994; no publication year inferred from those course dates.