Gravitation: master key to the universe ISBN 0-9689120-0-1 The book is out of print. Few remaining copies are stocked by The Distributors, 702 S. Michigan, South Bend, IN 46601; tel. 574-232-8500. Grevyt Press 704 - 15 Kensington Road Brampton, ON Canada  L6T 3W2 info@grevytpress.com