APA (7th ed.) Citation

Gattegno, C. (1969). Mathematics with numbers in colour. Educational Explorers.

Chicago Style (17th ed.) Citation

Gattegno, Caleb. Mathematics with Numbers in Colour. Educational Explorers, 1969.

MLA (8th ed.) Citation

Gattegno, Caleb. Mathematics with Numbers in Colour. Educational Explorers, 1969.

Warning: These citations may not always be 100% accurate.