Burroughs, E. R. (2010). A princess of mars. Project Gutenberg.
Cita Chicago Style (17a ed.)Burroughs, Edgar Rice. A Princess of Mars. To be supplied: Project Gutenberg, 2010.
Cita MLA (8a ed.)Burroughs, Edgar Rice. A Princess of Mars. Project Gutenberg, 2010.
Precaución: Estas citas no son 100% exactas.