APA-ийн эшлэл(7 дахь хэвлэлт)

Patricia Lauber. (1994). "Be a Friend to Trees (Let's-Read-and-Find-Out, Stage 2)" (Revised.). HarperCollins.

Чикаго-гийн эшлэл (17 дахь хэвлэлт)

Patricia Lauber. "Be a Friend to Trees (Let's-Read-and-Find-Out, Stage 2)". Revised. HarperCollins, 1994.

MLA -ийн эшлэл (9 дэх хэвлэлт)

Patricia Lauber. "Be a Friend to Trees (Let's-Read-and-Find-Out, Stage 2)". Revised. HarperCollins, 1994.