Probably from the canonical site, http://www.pianopractice.org/ http://www.pianopractice.org/, where a more up to date edition is available for free. The secon

Probably from the canonical site, http://www.pianopractice.org/ http://www.pianopractice.org/, where a more up to date edition is available for free. The second edition (that the submission link is based on) does contain that sentence, so it is from the original author. The third edition does not.