Biggs, E. E., & MacLean, J. R. (1969). Freedom to learn: An active learning approach to mathematics. Addison-Wesley Canada.
Cita Chicago (17th ed.)Biggs, Edith Ethel, i James R. MacLean. Freedom to Learn: An Active Learning Approach to Mathematics. Don Mills, Ont., Reading, MA: Addison-Wesley Canada, 1969.
Cita MLA (9th ed.)Biggs, Edith Ethel, i James R. MacLean. Freedom to Learn: An Active Learning Approach to Mathematics. Addison-Wesley Canada, 1969.
Atenció: Aquestes cites poden no estar 100% correctes.