Sherraden, M. S., Stringham, J., Sow, S. C., & McBride, A. M. (2006). The forms and structure of international voluntary service (CSD Working Paper No. 06-07). St. Louis, MO: Washington University, Center for Social Development. Subsequently published: Sherraden, M.S., Stringham, J., Costanza Sow, S., & McBride, A.M. (2006). Forms of international voluntary service: A sector of global civil society. Voluntas, 17(2), 156–173. doi:10.1007/s11266-006-9011-7