APA

Appleby E., . (2000). The three Billy-Goats Gruff a Norwegian Folktale =: Las tres cabras bruscas. New York: Scholastic Inc.

Chicago

Appleby Ellen, . 2000. The three Billy-Goats Gruff a Norwegian Folktale =: Las tres cabras bruscas. New York: Scholastic Inc.

Harvard

Appleby E., . (2000). The three Billy-Goats Gruff a Norwegian Folktale =: Las tres cabras bruscas. New York: Scholastic Inc.

MLA

Appleby Ellen, . The three Billy-Goats Gruff a Norwegian Folktale =: Las tres cabras bruscas. New York: Scholastic Inc. 2000.