[1] display/box/float/clear test (2007-03-02 23:52:25 +09:00) <https://www.w3.org/Style/CSS/Test/CSS1/current/test5526c.htm>

[2] CSS1 Test Suite: 5.5.26 clear (2007-03-02 23:52:25 +09:00) <https://www.w3.org/Style/CSS/Test/CSS1/current/sec5526c.htm>