Ackroyd, J. A. D. (2002). "Sir George Cayley, the Father of Aeronautics. Part 1. The Invention of the Aeroplane". Notes and Records of the Royal Society of London. 56 (2): 167–181. doi:10.1098/rsnr.2002.0176. JSTOR3557665. S2CID145644737.
Ackroyd, J. A. D. (2002). "Sir George Cayley, the Father of Aeronautics. Part 1. The Invention of the Aeroplane". Notes and Records of the Royal Society of London. 56 (2): 167–181. doi:10.1098/rsnr.2002.0176. JSTOR3557665. S2CID145644737.
Ackroyd, J. A. D. (2002). "Sir George Cayley, the Father of Aeronautics. Part 1. The Invention of the Aeroplane". Notes and Records of the Royal Society of London. 56 (2): 167–181. doi:10.1098/rsnr.2002.0176. JSTOR3557665. S2CID145644737.