Hydraulic Ram Pump - Pasali Philippines Foundation
fluid dynamics - How does an hydraulic ram pump work? - Physics Stack Exchange
How the Green and Carter water hydraulic ram pump works - also makers of Hydraulic rams, hydram, water powered pumps, vulcan ram, blake ram, easton ram and vacher ram.
Ram Pump (from Internet Glossary of Pumps)
Off Grid – World Water Rams
fluid dynamics - How does an hydraulic ram pump work? - Physics Stack Exchange