Gilbrich W.H Hydrological education during the fourth I H P phase(1990-1995) - Paris Unesco 1994 - 36p cm. - "International Hydrological Programme, Technical Documents in Hydrology" . Standard No.: 4231 Source: Reference Collections Subjects--Topical Terms: HydrographicalSurvey Dewey Class. No.: "U185, N4/UN"