"香港小學學習字詞表". www.edbchinese.hk. Retrieved April 19, 2018.
kakijun.jp
kakijun. "漢字の正しい書き順(筆順)". 漢字の正しい書き順(筆順). Retrieved April 19, 2018.
kangxizidian.com
Kangxi 1716, p. 41 See by example the radicals 卩, 厂 or 广. The 2007 common shape for those characters do not allow clearly to "guess" the stroke order, but old versions, visible on the Kangxi Zidian p.41 clearly allow us to guess the stroke order. Kangxi (1716), Kangxi Zidian 康熙字典