tp?Trade paperback. Any softcover book which is at least 7.25" (or 19 cm) tall, or at least 4.5" (11.5 cm) wide/deep.
Type: NONFICTION
Notes: There is an unpaginated page of text between pages "ix" and "1" (1 is also unnumbered).
At the bottom of the copyright page it reads "First Edition, August 1972 Paperback Printings: August 1972, April 1973".