All the things I know but of which I am not at the moment thinking. - 1:36 pm, 15 June 1969, New York.
piece by Robert Barry1 in 557,087, an exhibition curated by Lucy R. Lippard at the Seattle Art Museum in September/October 1969. [from the book Six Years: the dematerialization of the art object from 1966-1972...]
1.Robert Barry was interviewed about his work by Ursula Meyer on October 12, 1969. It's up at U B U W E B, and very much worth reading.