W Hegemann
Books
- No cover
United States Customs Service
1989
ISBN 9780160046124 
Upgrading of wastewater treatment plants
1991
ISBN 9780080407777
Upgrading of Wastewater Treatment Plants 1993 Volume 29/12
1996
ISBN 9780080425467
United States Customs Service
1989
ISBN 9780160046124Upgrading of wastewater treatment plants
1991
ISBN 9780080407777Upgrading of Wastewater Treatment Plants 1993 Volume 29/12
1996
ISBN 9780080425467