A good friend, Harmen Mesker, has taken the trouble to scan a very rare book by W.A. Sherrill, Heritage of Change – a Background to Chinese culture and Thinking, and is available in his site.
Sherrill is mostly know by his co-authorship with W.K. Chu. They wrote An Anthology of I Ching, which gives some divination techniques that are (sometimes loosely) associated with the Yijing, and The Astrology of I Ching, which is their adaptation of Heluo Lishu, a kind of numerological system that calculates birth and life hexagrams. They were both good friends with Nan Huaijin 南懷瑾, a well-known Buddhist teacher.