Johnson, D. A. (1956). How to use field trips in mathematics. National Council of Teachers of Mathematics.
Chicago (17e ed.) BronvermeldingJohnson, Donovan A. How to Use Field Trips in Mathematics. Washington, D. C: National Council of Teachers of Mathematics, 1956.
MLA (9e ed.) BronvermeldingJohnson, Donovan A. How to Use Field Trips in Mathematics. National Council of Teachers of Mathematics, 1956.
Let op: Deze citaties zijn niet altijd 100% accuraat.