Yes, of course, it's often useful when writing an article to quote from a previous authoritative source but there's a vast difference between quoting a few lines with an attribution to the original author and the apparent wholesale plagiarism of this case.
Apart from collaborating with him on the original book, I was a close friend of Don and, knowing him that well, am surprised at the suggestion that he would have given permission for his work to be copied in this fashion with no mention of the original book or author........
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