White, J. L.; Heidari, M. A.; Travis, M. H. (1995), "Experience in Rotor Balancing of Large Commercial Jet Engines", Proceedings of the 13th International Modal Analysis Conference, 2460, Boeing Commercial Airplane Group, fig .3, Bibcode:1995SPIE.2460.1338W
Foale 2007, p. 2, Fig. 2a. Foale, Tony (2007), Some science of balance(PDF), Tony Foale Designs: Benidoleig, Alicante, Spain, archived(PDF) from the original on 2013-12-27, retrieved 2013-11-04
Foale 2007, p. 6, Fig. 13. 360°-crank parallel twin. Foale, Tony (2007), Some science of balance(PDF), Tony Foale Designs: Benidoleig, Alicante, Spain, archived(PDF) from the original on 2013-12-27, retrieved 2013-11-04
Foale 2007, p. 6, Fig. 13. 180°-crank parallel twin. Foale, Tony (2007), Some science of balance(PDF), Tony Foale Designs: Benidoleig, Alicante, Spain, archived(PDF) from the original on 2013-12-27, retrieved 2013-11-04
Foale 2007, p. 2, Fig. 2a. Foale, Tony (2007), Some science of balance(PDF), Tony Foale Designs: Benidoleig, Alicante, Spain, archived(PDF) from the original on 2013-12-27, retrieved 2013-11-04
Foale 2007, p. 6, Fig. 13. 360°-crank parallel twin. Foale, Tony (2007), Some science of balance(PDF), Tony Foale Designs: Benidoleig, Alicante, Spain, archived(PDF) from the original on 2013-12-27, retrieved 2013-11-04
Foale 2007, p. 6, Fig. 13. 180°-crank parallel twin. Foale, Tony (2007), Some science of balance(PDF), Tony Foale Designs: Benidoleig, Alicante, Spain, archived(PDF) from the original on 2013-12-27, retrieved 2013-11-04