- Author: Robert Royal
- Language: English
- Year: 2000
- Author: Jean-Pierre Torrell Robert Royal
- Language: English
- Year: 1996
- Author: Virgil Nemoianu Robert Royal
- Language: English
- Year: 1991
- Author: Yves R. Simon Anthony O. Simon Robert Royal A. James McAdams
- Language: English
- Year: 2009