Corresponding elements, [64]

Counting, [1], [4]

Cross ratio, [46]

Darboux, [176], [186]

De Beaugrand, [170]

Degenerate pencil of rays of the second order, [58], [93]

Degenerate point-row of the second order, [56], [78]

De la Hire (1640-1718), [168], [171], 175

Desargues (1593-1662), [25], [26], [40], 121, [125], [162], [163], [164], [165], [166], 167, [168], [169], [170], [171], [174], [175]

Descartes (1596-1650), [162], [170], 171, [174], [176]