Villegas, A. E. (1987). A survey on the knowledge, attitude, and practice of family planning among population program professionals in Region XII. Socio-Economic Research Center, Notre Dame University.
Chicago-viite (17. p.)Villegas, Alfonso E. A Survey on the Knowledge, Attitude, and Practice of Family Planning Among Population Program Professionals in Region XII. Cotabato City: Socio-Economic Research Center, Notre Dame University, 1987.
MLA-viite (8. p.)Villegas, Alfonso E. A Survey on the Knowledge, Attitude, and Practice of Family Planning Among Population Program Professionals in Region XII. Socio-Economic Research Center, Notre Dame University, 1987.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.