Heuser, K. C. (1980). Freehand drawing and sketching: A training and work manual. Van Nostrand Reinhold.
Citazione stile Chigago Style (17a edizione)Heuser, Karl Christian. Freehand Drawing and Sketching: A Training and Work Manual. New York: Van Nostrand Reinhold, 1980.
Citatione MLA (9a ed.)Heuser, Karl Christian. Freehand Drawing and Sketching: A Training and Work Manual. Van Nostrand Reinhold, 1980.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.