Johnson, D. A. (1956). How to use field trips in mathematics. National Council of Teachers of Mathematics.
芝加哥风格引文Johnson, Donovan A. How to Use Field Trips in Mathematics. Washington, D. C: National Council of Teachers of Mathematics, 1956.
MLA引文Johnson, Donovan A. How to Use Field Trips in Mathematics. National Council of Teachers of Mathematics, 1956.
警告:这些引文格式不一定是100%准确.