Cita APA (7th ed.)

Lenchner, G., & Krulik, S. (1974). The overhead projector in the mathematics classroom. National Council of Teachers of Mathematics.

Cita Chicago (17th ed.)

Lenchner, George, i Stephen Krulik. The Overhead Projector in the Mathematics Classroom. Reston, VA: National Council of Teachers of Mathematics, 1974.

Cita MLA (9th ed.)

Lenchner, George, i Stephen Krulik. The Overhead Projector in the Mathematics Classroom. National Council of Teachers of Mathematics, 1974.