1977.03 All Double Combinations (Superimposed) of Six Geometric Figures (Circle, Square, Triangle, Rectangle, Trapezoid and Parallelogram)
1977.04 All Double Combinations (Superimposed) of Six Geometric Figures (Circle, Square, Triangle, Rectangle, Trapezoid and Parallelogram)
1977.05 Lines & Color. Straight, Not-Straight & Broken Lines Using All Combinations of Black, White, Yellow, Red and Blue for Lines and Intervals
1977.08 All Double Combinations (Superimposed) of Geometric Figures (Circle, Square, Triangle, Rectangle, Trapezoid, Parallelogram)
1978.01 Lines in Four Directions (Horizontal, Vertical, Diagonal Right and Diagonal Left) and All Their Combinations. Four Colors (Yellow, Black, Red and Blue) and All Their Combinations
1980.01 Color Grids. All Vertical & Horizontal Combinations of Black, Yellow, Red & Blue Straight, Not-Straight & Broken Lines