The print includes a reproduction of a fragment of the business card of Marvin Sackner. This broadside in an unfolded state together with other Ryosuke Cohen's Brain Cells and cards are stored in a large green & black folder. -- Source of annotation: Marvin or Ruth Sackner.

The rubber stamps were designed by Ken Friedman, Chuck Welch, Bill Gaglone, Steve Random, Luce Fierens, and Ed Varney on the occasion of an exhibition by Ken Friedman, entitled, Rubber Stamps, at Stamp Art Gallery in San Francisco. The original Friedman rubber stamp was designed by Wolfgang Feelish and became among the most widely reproduced stamp in international mail art networking. -- Source of annotation: Marvin or Ruth Sackner.

Anna Banana provides chapter outlines for a proposed book that describes and traces the history of artistamps from 1914 until the present. -- Source of annotation: Marvin or Ruth Sackner.

Estra Milman assisted in producing the catalogue and exhibition. This book reproduces a section of Friedman's diary of rubber stampings. -- Source of annotation: Marvin or Ruth Sackner.

The material in this exhibition was borrowed from the Artpool Archive. Geza Perneczky contributed an introduction. The Sackner Archive is listed in the reference section of overseas institutions "that deal with the archivation of Mail Art material." The cover of one copy is rubberstamped with the name and address of Geza Perneczky, the other is not. It is filed under its English title, "Stamp Images." -- Source of annotation: Marvin or Ruth Sackner.