Design Study of Shaft Face Seal with Self-acting Lift Augmentation John Zuk, Lawrence P. Ludwig, and Robert L. Johnson.John Zuk, Lawrence P. Ludwig, Robert Lewis Johnson1970EN
Experimental Study of Pump and Seal Characteristics of Helical Groove Geometry Incorporated in a Combined Bearing and Pump / Lawrence P. Ludwig, Thomas N. Strom, and Robert L. Johnson.Lawrence P. Ludwig1969EN
Improved Circumferential Shaft Seal for Aircraft Gear Transmissions by Lawrence P. Ludwig and Thomas N. Strom.Lawrence P. Ludwig1973EN