- Author: Spike Paul, Spike Robert Warren
- Language: English
- Year: 2016
- Author: Robert Warren Erickson
- Language: English
- Year: 2001
- Author: Ken Hill, Daniel B Levine, Robert Warren, National Research Council (U.S.). Panel on Immigration Statistics
- Language: English
- Year: 1985
- Author: Robert Warren Howarth Jacqueline E. Mohan
- Language: English
- Year: 2013
- Author: George H Muller, Robert Warren Kirk
- Language: English
- Year: 1976