International
Tables for
Crystallography
Volume A
Space-group symmetry
Edited by M. I. Aroyo

International Tables for Crystallography (2016). Vol. A, ch. 2.1, p. 157

Figure 2.1.3.8 

Th. Hahna and A. Looijenga-Vosb
[Figure 2.1.3.8]
Figure 2.1.3.8

Trigonal P and hexagonal P space groups ([\hbox{\sf G}] = general-position diagram).