According to the Library of Congress, there were two different authors called Bill Ward producing graphic art and erotica (#1 and #3).
#1 Bill Ward 1919-1998, The Glamour Girls of Bill Ward
#2 Bill (Bill Henry) Ward, New Zealand gardening writer, House plants, hanging baskets and window boxes
. (Dirty secrets
is a gardening book by this author, not erotica by #1 or #3.)
#3 Bill Ward, died July 24 1996, graphic artist known for producing educational materials for children and erotic images for homosexual publications; The Fantastic World Of Bill Ward - Volume 3
#4 Bill Ward, fantasy author, The Wyrd Of War
#5 is probably the same guy as #4, and is the owner of http://billwardwriter.com