1. Bosserman, P., & Gagan, R. (1972). Leisure and voluntary action. In D. H. Smith (Ed.), Voluntary action research: 1972 (pp. 109–126). D.C. Heath.
2. Boulding, K. (1973). The economy of love and fear. Wadsworth.
3. Cheng, E., Stebbins, R., & Packer, J. (2017). Serious leisure among older gardeners in Australia. Leisure Studies, 36(4), 505–518.
4. Darby, P., & Clough, P. (2013). Investigating the information-seeking behaviour of genealogists and family historians. Journal of Information Science, 39(1), 73–84.
5. Dickson, A. (1974). Foreword. In D. H. Smith (Ed.), Voluntary action research: 1974 (pp. xiii–xx). D.C. Heath.