BARNEVELD, Aart van. Six Mail Art Projects / Zes Post-Kunst Projekten.

(Amsterdam): Stempelplaats, 1980.  Octavo.  Unpaginated.  Special volume issued as Rubber Volume 3 issues 7-9.  Nice documentation of six mail art projects that were exhibited at Stempelplaats.  Includes work by Ulises Carrion, Leonhard Frank Duch, Pawel Petasz I and others.  Illustrated throughout.  A very good copy in wrappers.  Published in an edition of 500 copies.