v. 1. International economics, 1933 and The trade cycle, 1936 and introduction to the collection by Peter Oppenheimer
v. 2. Towards a dynamic economics, 1948 and Economic dynamics, 1973
v. 3. The life of John Maynard Keynes, 1951
v. 4. Economic essays, second edition, 1972
v. 5. Topical comment: essays in dynamic economics applied, 1961
v. 6. The dollar, 1953 and Reforming the world's money, 1965
v. 7. Money, 1969.
OBNB doesn't sell books, but you may be able to find a copy at one of these websites:
Sir Roy Harrod's writings on economics by Roy Harrod. ISBN 1403917434. Published by Palgrave Macmillan in 2003. Publication and catalogue information, links to buy online and reader comments.
