Frederick, H. V. (2012). Once upon a toad. Simon & Schuster Books for Young Readers.
Lua i Stíl Chicago (17ú heag.)Frederick, Heather Vogel. Once upon a Toad. New York: Simon & Schuster Books for Young Readers, 2012.
Lua MLA (8ú heag.)Frederick, Heather Vogel. Once upon a Toad. Simon & Schuster Books for Young Readers, 2012.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.