Toronto Mail Order Staff. (1990). "Questions Kids Ask About This and That (Questions Kids Ask, 27)". Grolier Limited.
Chicago-referens (17:e uppl.)Toronto Mail Order Staff. "Questions Kids Ask About This and That (Questions Kids Ask, 27)". Grolier Limited, 1990.
MLA-referens (9:e uppl.)Toronto Mail Order Staff. "Questions Kids Ask About This and That (Questions Kids Ask, 27)". Grolier Limited, 1990.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.