Cita APA (7th ed.)

Tupikova, I., & Geus, K. (2013). The Circumference of the Earth and Ptolemy's World map: Irina Tupikova & Klaus Geus. Max-Planck.Institu für Wissenschaftsgeschichte.

Cita Chicago (17th ed.)

Tupikova, Irina, i Klaus Geus. The Circumference of the Earth and Ptolemy's World Map: Irina Tupikova & Klaus Geus. Berlin: Max-Planck.Institu für Wissenschaftsgeschichte, 2013.

Cita MLA (8th ed.)

Tupikova, Irina, i Klaus Geus. The Circumference of the Earth and Ptolemy's World Map: Irina Tupikova & Klaus Geus. Max-Planck.Institu für Wissenschaftsgeschichte, 2013.