Daniel Sonkin's knowledge about domestic violence comes from his high years as a psychotherapist working with men who batter women, as well as an educator, administrator, and consultant with battered women's shelters, law enforcement agencies, military programs, criminal justice and medical personnel. Del Martin is considered by many to be the founder of the battered women's movement, with the publication of the internationally acclaimed, "Battered Wives." Leonora Walker was the first clinician to write extensively about domestic violence from a psychological perspective and her book, "The Battered Woman," is considered the definitive text on counseling the victim of abuse.