Dr. Randy O. Frost is the Harold and Elsa Siipola Israel Professor of Psychology at Smith College and author of "Stuff: Compulsive Hoarding and the Meaning of Things" (Houghton, Mifflin, Harcourt, 2010), a book about hoarding for the general public. He is an expert on obsessive-compulsive disorder and compulsive hoarding and has published more than 100 scientific articles on these topics. He other books include "Compulsive Hoarding and Acquiring: Therapist Guide and Workbook" as well as "Buried in Treasures: Help for Compulsive Acquiring, Saving, and Hoarding" (both published by Oxford University Press in 2007).
A good book to know hom much cognitive approaches out there to explain OCD symptoms including the measures. But the languange is too hard to be comprehend by me, not a native obviously. And they're missing metacognitive approach.