- Author: Straffin Philip D
- Language: English
- Year: 2010
- Author: Sinkov Abraham
- Language: English
- Year: 2009
- Author: Sawyer W. W
- Language: English
- Year: 2014
- Author: Salkind C. T
- Language: English
- Year: 2014
- Author: Salkind Charles T., Earl James Mayberry, Mathematical Association of America., Gaglione Anthony M., Maurer Stephen B., Shell Niel, Berzsenyi George, Artino Ralph A., Schneider Leo J
- Language: English
- Year: 1961
- Author: Ore Øystein
- Language: English
- Year: 2017
- Author: Olds Carl D
- Language: English
- Year: 2014
- Author: Niven Ivan Morton, Mathematical Association of America
- Language: English
- Year: 1965
- Author: Edward W. Packel
- Language: English
- Year: 2006
- Author: McCleary John
- Language: English
- Year: 2018