Cita APA (7th ed.)

Thybony Scot & Chesley, P. The rockies: Pillars of a continent. D.C..

Cita Chicago (17th ed.)

Thybony Scot i Paul Chesley. The Rockies: Pillars of a Continent. Washington: D.C..

Cita MLA (9th ed.)

Thybony Scot i Paul Chesley. The Rockies: Pillars of a Continent. D.C..