National Science Teachers Association & ebrary, Inc. (2001). Dig in!: Hands-on soil investigations. NSTA Press.
芝加哥风格引文National Science Teachers Association 与 Inc ebrary. Dig in!: Hands-on Soil Investigations. Arlington, Va.: NSTA Press, 2001.
MLA引文National Science Teachers Association 与 Inc ebrary. Dig in!: Hands-on Soil Investigations. NSTA Press, 2001.
警告：这些引文格式不一定是100％准确.