Three books that are reasonable:
1. The Interaction between Geometry and Performance of a Centrifugal Pump, by B. Neumann MEP Limited, ISBN 0-85298-755-2
2. Centrifugal Pumps Design and Application, Lobanoff and Ross, ISBN 0-87201-190-9
3. Centrifugal Pup Design, John Tuzson, ISBN...