Billups, A. (1980). Perspectives: Discussion starters on attitudes and values for church groups. Judson.
Chicago-viite (17. p.)Billups, Ann. Perspectives: Discussion Starters on Attitudes and Values for Church Groups. Valley forge: Judson, 1980.
MLA-viite (9. p.)Billups, Ann. Perspectives: Discussion Starters on Attitudes and Values for Church Groups. Judson, 1980.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.