Mannheim and Polyphase Slide Rules; Complete Manual with Tables of Settings, Equivalents and Gauge PointsWilliam E. Breckenridge · First published 2023Open the Tome
The polyphase slide rule, slide rule no. N 4053William E. Breckenridge · First published 1938Open the Tome
The polyphase duplex slide ruleWilliam E. Breckenridge, Keuffel & Esser Co · First published 1924Open the Tome
