1. Subchapter C — Aircraft, Part 27 Airworthiness standards: normal category rotorcraft, Subpart D — Design and construction, Section 27.621 Casting factors, Federal Aviation Administration, Department of Transportation 1997, Washington, DC.
2. J. Campbell: ‘Castings practice: the 10 rules of casting’; 2004, Oxford, Elsevier Butterworth-Heinemann.