(2001). The Environment encyclopedia and directory (3rd ed.). Europa Publications Limited.
Citazione stile Chigago Style (17a edizione)The Environment Encyclopedia and Directory. 3rd ed. London: Europa Publications Limited, 2001.
Citatione MLA (9a ed.)The Environment Encyclopedia and Directory. 3rd ed. Europa Publications Limited, 2001.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.