- Opus 26, 1989/90: Quartette, Modell 1-9
- Elisabeth Kaufmann / Galerie Metropol, Basel / Wien, 1990
- 111 sheets in a linen-covered box with 2 audio CDs
- edition of 50, initialed and numbered
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- Opus 26, 1989/90: Quartette, Modell 1-9
- Elisabeth Kaufmann / Galerie Metropol, Basel / Wien, 1990
- 111 sheets in a linen-covered box with 2 audio CDs
- edition of 50, initialed and numbered
- Ask
Opus 26 quartet model 1–9, with Friedrich Stoppa
contexts：
- The Location of Straight, Not-Straight & Broken Lines and all their Combinations
- Sol LeWitt
- John Weber Gallery, New York, 1976 ⁄ softcover
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- Ruthenbeck
- Reiner Ruthenbeck
- Kabinett für aktuelle Kunst, Bremerhaven, 1974 ⁄ exhibition poster. screen printed 50 x 47,8 cm
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- Brick Wall
- Sol LeWitt
- Tanglewood Press, New York, 1977 ⁄ softcover
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- Het werkwoord mensen : vier maal vier maal vier maal vervoegd : 64 taalsels
- Ubbo-Derk Hakholt
- bloknoot, Arnhem, 1974 ⁄ staple-bound
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