APA (7th ed.) Citation

Hill, T. J. (1974). Mathematical challenges II: Plus six. National Council of Teachers of Mathematics.

Chicago Style (17th ed.) Citation

Hill, Thomas J. Mathematical Challenges II: Plus Six. Reston, VA: National Council of Teachers of Mathematics, 1974.

MLA (9th ed.) Citation

Hill, Thomas J. Mathematical Challenges II: Plus Six. National Council of Teachers of Mathematics, 1974.

Warning: These citations may not always be 100% accurate.