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

International Tables for Crystallography (2015). Vol. A, ch. 1.4, p. 72

Figure 1.4.5.4 

B. Souvignierd
[Figure 1.4.5.4]
Figure 1.4.5.4

Orthogonal projection along [001] of the symmetry-element diagram for [Pmn2_1] (31) (top) and the diagram for plane group p2mg (7) (bottom).