- Author: F. Collot (auth.) Julia G. Vassileva-Popova (eds.)
- Language: English
- Year: 1975
- Author: Bas Aarts David Denison Evelien Keizer Gergana Popova
- Language: English
- Year: 2004
- Author: Elena Popova
- Language: English
- Year: 2008
- Author: Popova M. Seymour D.
- Language: English
- Year: 2003
- Author: Bas Aarts David Denison Evelien Keizer Gergana Popova
- Language: English
- Year: 2004
- Author: Bas Aarts David Denison Evelien Keizer Gergana Popova
- Language: English
- Year: 2004
- Author: David, Popova Maria Seymour
- Language: English
- Year: 2004
- Author: Popova et al.
- Language: English