Parr, G. D. A. (1903). Electrical engineering measuring instruments for commercial and laboratory purposes. Blackie & Son.
Lua i Stíl Chicago (17ú heag.)Parr, George Dudley Aspinall. Electrical Engineering Measuring Instruments for Commercial and Laboratory Purposes. London, Glasgow [etc.]: Blackie & Son, 1903.
Lua MLA (8ú heag.)Parr, George Dudley Aspinall. Electrical Engineering Measuring Instruments for Commercial and Laboratory Purposes. Blackie & Son, 1903.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.