The drawn line in painting: line as form. Elise Asher, Rosemarie Castro, Porfirio DiDonna, Jane Logemann, Agnes Martin, Robert Oppenheim, Stephen Rosenthal, Cy Twombly, Mario Yrisary. Parker Street 470, Boston Massachusetts, April 6 – May 1, 1971 Harcus-Krakow Gallery / Obelisk Gallery: A joint venture