- Author: Michele M. Tugade, Michelle N. Shiota, Leslie D. Kirby, Barbara L. Fredrickson
- Language: English
- Year: 2014
- Author: Barbara L. Fredrickson Ph.D
- Language: English
- Year: 2013
- Author: Barbara L. Fredrickson Ursula Nuber Nicole Hölsken
- Language: German
- Year: 2011