I found several listings at abebooks.com when I typed in "Neuhaus, Heinrich" as author. This was the cheapest of the Leibovitch translations, published by Barre & Jenkins, 1973, the only edition I've seen cited in the piano literature. In the past, I've seen other listings online that were cheaper, but the translator and/or publisher were either not given or another publisher was noted. Unfortunately, there's no ISBN number printed in Barre & Jenkin's 1973 edition to help with identification. Buyer, beware!
The Art of Piano Playing. Translated by K.A.Leibovitch.
NEUHAUS, HEINRICH
Bookseller: de Friedesche molen
(Amsterdam, NH, Netherlands)
Bookseller Rating:
Quantity Available: 1
Book Description: London, Barre & Jenkins 1973. Or.cl. w. dustwr. XIII, 240 pp. Bookseller Inventory # 24540
Price: US$ 34.83
Convert Currency
Shipping: US$ 19.62
From Netherlands to U.S.A.
Nothing is said about the condition of this book. Others, with prices up to $125.00 plus shipping are described more fully. Look at all three pages of abebook.com's listings to see more, including other languages than English and similar titles by Neuhaus.
Good luck
viridian