Figure 4.26

Hannes Grobe 19:09, 3 September 2006 (UTC)
(https://commons.wikimedia.org/wiki/File:Rhodes_meander_hg.jpg), "Rhodes meander hg", Editing, https://creativecommons.org/licenses/by-sa/2.5/legalcode

Figure 4.28

Theon (https://commons.wikimedia.org/wiki/File:Frise_exemple.svg), https://creativecommons.org/licenses/by-sa/4.0/legalcode