1. ISO 4391:1983(1983).Hydraulic Fluid Power—Pumps Motors and Integral Transmissions—Parameter Definitions and Letter Symbols. Switzerland: ISO.
2. ISO 3662:1976(1976).Hydraulic Fluid Power—Pumps and Motors—Geometric Displacements. Switzerland: ISO.
3. ISO 8426:2008(2008).Hydraulic Fluid Power—Positive Displacement Pumps and Motors—Determination of Derived Capacity. Switzerland: ISO.