The most interesting thing about this publisher is that they produced the first modern mass-market paperback books.and were a great influence on Penguin Books. (Info from Wikipedia)
Hardcover edition published in 1932 by Harper & Brothers, Publishers.
First Perennial Library edition published in 1969. Reset 1989.
First Perennial Classics edition published in 1998.
First Harper Perennial Modern Classics edition published in 2006. (this comment is from another edition of this book)
harpercollins imprint p/b, still using the 1977 panther/granada/grafton isbn and setting, and
cover art by heinrich hoerle
cover price £3.99, australia $9.95, new zealand $14.95, canada $6.50
208pp. including titles, indica etc, end pp. advertising (this comment is from another edition of this book)