Between 1967 and 1970, Petaja published five portfolios of Bok's art. Those portfolios include "Variations on Bok Theme", (black & white portfolio, 1967); "The Famous Power Series", (black & white portfolio, with text by Bok, 1969); and "A Memorial Portfolio", (color portfolio, with booklet with text by Petaja, 1970). Petaja also authored a commemorative volume, "And Flights of Angels: The Life and Legend of Hannes Bok" (Bokanalia Memorial Foundation, 1968). Along with brief contributions from Roger Zelazny, Jack Gaughan, Donald Wollheim and others, "And Flights of Angels" contains Petaja's long biographical essay on the artist, a checklist of Bok's published artwork and writings, and reproductions of a substantial number of the artist's drawings, prints and illustrations. Later, under the SISU imprint (and on behalf of the Bokanalia Foundation), Petaja published an illustrated volume of Bok's poetry, "Spinner of Silver and Thistle" (1972), as well as editing "The Hannes Bok Memorial Showcase of Fantasy Art" (1974).