1.Gallery Without Gravity, 1976 oil on paper, 42x28 in./106x71 cm.      2.Blue Cathedral 1974 gouache on paper 33x22 in./84x56 cm.      3.Trinity in White, 1976 oil on paper 42x28 in./106x71 cm.      4.Glass Tunnel, 1976 oil on paper 42x28 in./106x71 cm.