Nazca , 1987. Cork on chipboard. 12 9/16 x 16 1/8 in. (32 x 41 cm)

Sistemas Cromáticos Primarios y Secundarios , 1971. Colored thread on board. 29 1/2 x 22 3/4 in. (74.93 x 57.79 cm)

Línea Blanca , 1987. Spackle and paint on wood. 9 7/16 x 13 3/8 in. (24 x 34 cm)

Línea Blanca , 1987. Spackle and paint on wood. 10 x 11 3/4 in. (25.5 x 30 cm)

Untitled , 1977. Acrylic on paper. 18 1/16 x 24 3/8 in. (46 x 62 cm)

Sistema (Ele) , 1968. Acrylic on metal, acrylic and graphite on paper. Three metal elements: 19 2/3 in. (100 x 50 x 50 cm) each; Three metal elements: 19 2/3 x 39 1/3 x 19 2/3 in. (50 x 100 x 50 cm) each; Drawing: 22 x 29 in. (56 x 76 cm)

Sistema cromático - primarios - , 1968. Graphite and acrylic on paper. 19 x 24 in. (48.3 x 61 cm)

Escala en rojo y primarios , 1968. Acrylic on canvas. 11 pieces, 14 9/16 x 14 9/16 in. (37.1 x 37.1 cm) each

Sistema de color , 1968. Graphite and acrylic on paper. 26 x 19 in. (66.04 x 48.26 cm)

Sistema cromático , 1971. Cotton thread, paint and wood. 21 1/4 x 25 3/16 in. (54 x 64 cm)

Sistema de color , 1969. Acrylic and graphite on paper. 16 7/8 x 25 1/2 in. (42.9 x 64.8 cm)

The Birren's Triangles , 1970. Acrylic and graphite on paper. 18 7/8 x 24 in. (48 x 61 cm)

Untitled , 1974. Acrylic on canvas. 19 5/8 x 27 1/2 in. (50 x 70 cm)

Ruyala , 2001. Acrylic on canvas. 17 11/16 x 29 9/16 in. (45 x 60 cm)