BLUEBIRD BOOKS. (2001). CHILDREN'S REFERENCE: THE UNIVERSE. BLUEBIRD BOOKS.
Citazione stile Chigago Style (17a edizione)BLUEBIRD BOOKS. CHILDREN'S REFERENCE: THE UNIVERSE. NEW DELHI: BLUEBIRD BOOKS, 2001.
Citatione MLA (9a ed.)BLUEBIRD BOOKS. CHILDREN'S REFERENCE: THE UNIVERSE. BLUEBIRD BOOKS, 2001.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.