Note that in modern Traditional Chinese, Simplified Chinese and Japanese, radical ice in some characters (e.g. 冬, 寒) is now written as two dots. Their original forms are retained in Korean hanja and some old Traditional Chinese typefaces (e.g. 冬, 寒).
Fazzioli, Edoardo (1987). Chinese calligraphy : from pictograph to ideogram : the history of 214 essential Chinese/Japanese characters. calligraphy by Rebecca Hon Ko. New York: Abbeville Press. ISBN0-89659-774-1.
Leyi Li: “Tracing the Roots of Chinese Characters: 500 Cases”. Beijing 1993, ISBN978-7-5619-0204-2
GF 0011-2009 Table of Indexing Chinese Character Components prescribes 201 principle indexing components and 100 associated indexing components (in brackets) used in Simplified Chinese. Not all associated indexing components are listed above.