Wiehe's book covers other aspects of sibling abuse, such as emotional and physical abuse, and spends more time on abuse of girls than of boys. It has also been criticized for viewing the subject in terms of a feminist agenda rather basing it on solid scientific research. So I'm not sure you would get your money's worth if you're a guy who was sexually abused by his big brother.
I would have gone for another book, Sibling Abuse Trauma: Assessment and Intervention Strategies for Children, Families, and Adults, by John Caffaro and Allison Conn-Caffaro, which is less than half as expensive and focused more on sexual abuse.
But sure, get some other opinions, and depending where you are in Jersey you might be able to see these books in a large public or university library near you.
Nobody living can ever stop me
As I go walking my freedom highway.
Nobody living can make me turn back:
This land was made for you and me. (Woody Guthrie)