^"Aviation History". مؤرشف من الأصل في 2017-06-17. اطلع عليه بتاريخ 2009-07-26. In 1799 he set forth for the first time in history the concept of the modern aeroplane. Cayley had identified the drag vector (parallel to the flow) and the lift vector (perpendicular to the flow).
^"Sir George Cayley (British Inventor and Scientist)". Britannica. مؤرشف من الأصل في 2015-04-26. اطلع عليه بتاريخ 2009-07-26. English pioneer of aerial navigation and aeronautical engineering and designer of the first successful glider to carry a human being aloft. Cayley established the modern configuration of an aeroplane as a fixed-wing flying machine with separate systems for lift, propulsion, and control as early as 1799.
