Cita APA (7th ed.)
Higgins, P. M. (2008). Number story: From counting to cryptography. Copernicus Books.
Cita Chicago (17th ed.)
Higgins, Peter M. Number Story: From Counting to Cryptography. London: Copernicus Books, 2008.
Cita MLA (9th ed.)
Higgins, Peter M. Number Story: From Counting to Cryptography. Copernicus Books, 2008.
Atenció: Aquestes cites poden no estar 100% correctes.