Não informado. (1988). Federation Highlights. Water Pollution Control Federation.
Chicago-viite (17. p.)Não informado. Federation Highlights. Alexandria, Va: Water Pollution Control Federation, 1988.
MLA-viite (8. p.)Não informado. Federation Highlights. Water Pollution Control Federation, 1988.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.