International
Tables for Crystallography Volume C Mathematical, physical and chemical tables Edited by E. Prince © International Union of Crystallography 2006 
International Tables for Crystallography (2006). Vol. C, ch. 9.2, p. 768
Figure 9.2.2.9
S. Ďurovič^{a}


Figure 9.2.2.9
The nine possible displacements in the structures of polytypes of phyllosilicates. The individual vectors are designated by their conventional numerical characters and the signs +, −. The zero displacement <*> is not indicated. The relations of these vectors to the basis vectors a_{1}, a_{2} or a, b are evident. 