|
WO9721915A1
|
|
Propulsion engine driven by rotary rockets
|
|
DE19631473A1
|
|
Internal combustion engine
|
|
US4931183A
|
|
Process and apparatus for the biological purification of water
|
|
EG13963A
|
|
Method for supplying water to water deficient areas and plant for performing the method
|
|
DE2437329A1
|
|
Fresh-water-induced swimming pool bottom - above hollow space for fresh water connected with it by apertures
|
|
DE2329279A1
|
|
Biochemical sewage treatment using oxygen - at feed rate controlled by oxygen consumption of microorganisms
|
|
DE1911199A1
|
|
Deacidification of water
|
