- Author: David A. Lake (editor), Robert Powell (editor)
- Language: English
- Year: 2020
- Author: Robert Powell
- Language: English
- Year: 2020
- Author: David A. Lake, Robert Powell
- Language: English
- Year: 1999
- Author: David A. Lake Robert Powell
- Language: English
- Year: 1999
- Author: Robert Powell
- Language: English
- Year: 2002
- Author: Robert Powell
- Language: English
- Year: 1999
- Author: Robert Powell Jim Laurier
- Language: English
- Year: 2004
- Author: Robert Powell Jim Laurier
- Language: English
- Year: 2004
Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition
pdf
- Author: Robert Powell, Roger Conant, Joseph T. Collins
- Language: English
- Year: 2016
- Author: Anonymous, Robert Powell, Valentin Tomberg
- Language: English
- Year: 2009