May-Len Skilbrei and Marlene Spanger have edited the book Prostitution Research in Context: Methodology, Representation and Power, published by Routledge. Spanger and Skilbrei have written the chapter "Exploring sex for sale: Methodological concerns". May-Len Skilbrei has also written the chapter "Speaking the truth about prostitution".
Read more about the book on the publisher's website (link)