Spencer, W.G. Inventional geometry : a series of problems : intended to familiarize the pupil with geometrical conceptions, and to exercise his inventive faculty / by William George Spencer , with a prefatory note by Herbert Spencer; W.G. Spencer .— : D. Appleton and Company, 1883 .— 96 с. — Lang: eng .— URL: https://rucont.ru/efd/109840 (дата обращения: 16.07.2024)