International
Tables for Crystallography Volume A Spacegroup symmetry Edited by Th. Hahn © International Union of Crystallography 2006 
International Tables for Crystallography (2006). Vol. A, ch. 4.2, p. 61

Comparative tables for the 17 plane groups first appeared in IT (1952). The classification of plane groups is discussed in Chapter 2.1 . Table 4.2.1.1 lists for each plane group its system, lattice symbol, point group and the planegroup number, followed by the short, full and extended Hermann–Mauguin symbols. Short symbols are included only where different from the full symbols. The next column contains the full symbol for another setting which corresponds to an interchange of the basis vectors a and b; it is only needed for the rectangular system. Multiple cells c and h for the square and the hexagonal system are introduced in the last column.

References
International Tables for Xray Crystallography (1952). Vol. I, edited by N. F. M. Henry & K. Lonsdale. Birmingham: Kynoch Press. [Abbreviated as IT (1952).]