Patricia Lauber. (1994). "Be a Friend to Trees (Let's-Read-and-Find-Out, Stage 2)" (Revised.). HarperCollins.
Chicago (17e ed.) BronvermeldingPatricia Lauber. "Be a Friend to Trees (Let's-Read-and-Find-Out, Stage 2)". Revised. HarperCollins, 1994.
MLA (9e ed.) BronvermeldingPatricia Lauber. "Be a Friend to Trees (Let's-Read-and-Find-Out, Stage 2)". Revised. HarperCollins, 1994.
Let op: Deze citaties zijn niet altijd 100% accuraat.