Cita APA (7th ed.)

LEVETE, S. (2010). ENERGY OUR WORLD: GAS. S.CHAND PUBLISHING.

Cita Chicago (17th ed.)

LEVETE, SARAH. ENERGY OUR WORLD: GAS. NEW DELHI: S.CHAND PUBLISHING, 2010.

Cita MLA (9th ed.)

LEVETE, SARAH. ENERGY OUR WORLD: GAS. S.CHAND PUBLISHING, 2010.