en Ball, D.G. (), „A generalisation of π”, Mathematical Gazette, 57 (402): 298–303, doi:10.2307/3616052, Griffiths, David; Culpin, David (), „Pi-optimal polygons”, Mathematical Gazette, 59 (409): 165–175, doi:10.2307/3617699
en Gerdes, Paulus (), „On culture, geometrical thinking and mathematics education”, Educational Studies in Mathematics, 19 (2): 137–162, doi:10.1007/bf00751229, JSTOR3482571
en Gerdes, Paulus (), „On culture, geometrical thinking and mathematics education”, Educational Studies in Mathematics, 19 (2): 137–162, doi:10.1007/bf00751229, JSTOR3482571
en Silvester, John R. (), „Extensions of a theorem of Van Aubel”, The Mathematical Gazette, 90 (517): 2–12, JSTOR3621406
