- Sewage--Purification--Periodicals (4)
- Water quality management--Periodicals (2)
- Water--Pollution--Periodicals (2)
- Environmental protection--Periodicals (1)
- Pollution--Periodicals (1)
- Sanitary engineering--Periodicals (1)
- Water chemistry--Periodicals (1)
- Water--Purification--Periodicals (1)
- Water-supply--Periodicals (1)