APA (7e ed.) Bronvermelding
National Science Teachers Association & ebrary, Inc. (2001). Dig in!: Hands-on soil investigations. NSTA Press.
Chicago (17e ed.) Bronvermelding
National Science Teachers Association en Inc ebrary. Dig in!: Hands-on Soil Investigations. Arlington, Va.: NSTA Press, 2001.
MLA (9e ed.) Bronvermelding
National Science Teachers Association en Inc ebrary. Dig in!: Hands-on Soil Investigations. NSTA Press, 2001.
Let op: Deze citaties zijn niet altijd 100% accuraat.