APA

humphrey p., willey l., . (1994). Nature's Wonders. london: Evans brothers limited.

Chicago

humphrey paul, willey lynne, . 1994. Nature's Wonders. london: Evans brothers limited.

Harvard

humphrey p., willey l., . (1994). Nature's Wonders. london: Evans brothers limited.

MLA

humphrey paul, willey lynne, . Nature's Wonders. london: Evans brothers limited. 1994.