- Author: Robert Campbell Peter Vanderwarker
- Language: English
- Year: 1992
- Author: Robert Campbell
- Language: English
- Year: 2011
- Author: Robert Campbell, Ken Wytsma, Meg Campbell, Caleb Campbell
- Language: English
- Year: 2016
- Author: Robert Campbell
- Language: English
- Year: 2008
- Author: Robert Campbell Moberley
- Language: English
- Year: 2010
- Author: Robert Campbell Moberley
- Language: English
- Year: 2010
- Author: Norman Robert Campbell
- Language: English
- Year: 1920
- Author: Zimmer Heinrich Robert, Campbell Joseph
- Language: English
- Year: 1992
- Author: Alan Kitson Robert Campbell (auth.)
- Language: English
- Year: 1996
- Author: Zimmer Heinrich Robert, Campbell Joseph
- Language: English
- Year: 1992