<command arg="-root"/>
+ <video href="https://www.youtube.com/watch?v=c2gvyGVNG80"/>
+
<hgroup>
<select id="kleinbottle">
<option id="random" _label="Random shape"/>
"Beyond the Third Dimension: Geometry, Computer Graphics, and Higher
Dimensions", Scientific American Library, 1990.
-http://en.wikipedia.org/wiki/Klein_bottle
+https://en.wikipedia.org/wiki/Klein_bottle
Written by Carsten Steger; 2008.
</_description>