De Hepta-Cirkelomtrek Onderverdeeld in Hepta-Quadranten ten Grondslag aan Fra Angelico's "Gesu Portato al Sepolcro" ... The Hepta-circumference subdivided into hepta-quadrants basic to Fra Angelico's "Gesu Portato al Sepolcro", etc.
Haas, Karel H. de.
Rotterdam :  Privately printed, 
1949.