APA

Schramm B. G., Casares M. & Lance V. A. (1999). Steroid levels and reproductive cycle of the Galápagos tortoise, Geochelone nigra, living under seminatural conditions on Santa Cruz Island (Galápagos). : .

Chicago

Schramm Beatrix G, Casares M and Lance Valentine A. 1999. Steroid levels and reproductive cycle of the Galápagos tortoise, Geochelone nigra, living under seminatural conditions on Santa Cruz Island (Galápagos). : .

Harvard

Schramm B. G., Casares M. and Lance V. A. (1999). Steroid levels and reproductive cycle of the Galápagos tortoise, Geochelone nigra, living under seminatural conditions on Santa Cruz Island (Galápagos). : .

MLA

Schramm Beatrix G, Casares M and Lance Valentine A. Steroid levels and reproductive cycle of the Galápagos tortoise, Geochelone nigra, living under seminatural conditions on Santa Cruz Island (Galápagos). : . 1999.