References and Credit for the information on this web site:
This pages on this web site are compiled with the informatin that we obtained through the researches of the internet, books, dictionaries, and magazines Our apologies if we are not able to list all the web sites, books, magazines and other reference materials here.

[0] http://www.learnthat.org/vocabulary/pages/view/roots.html a word tutoring web site
[1] Word Clues by Amsel Greene, Harper & Row, Publishers
This is an excellent book, available from http://www.amazon.com. However, given that Chinese language is not belonging to Indo-European Language Family Tree, this book is simply too difficult for Chinese people, who rarely hear of Greek roots or Latin roots, and who will hardly believe when they are told that 80% of English words are not actually originated from English itself but from Greek or Latin. Another problem is that the example words listed in this book are too difficult. Chinese people will not be able to appreciate the value of this book with the difficult example words. Some roots and example words are based on this book.
[2] http://www.merriam-webster.com/
Thankfully the web site provides hints about how to dissect an English word into Greek or Latin roots. However this dictionary does not pay attention to prefix or suffix in a word. Without identifying prefix or suffix first, it is difficult to decipher root correctly in a word.
[3] The Merriam-Webster New Book of Word Histories by Merriam-Webster, available from http://www.amazon.com. Some roots and example words are based on this book.
[4] How to Increase your Word Power by Yugui Zhan, Liutong Culture Enterprise Ltd. This book is less difficult than reference [1].
[5] http://dict.cn/
Chinese meanings for many example words listed on this web site are based on the site.
[6] Essential English-Chinese Dictionary from http://www.lingoes.net/
Chinese meanings for many example words listed on this web site are based on the site.
[7] http://www.tigernt.com/dict.shtml
Chinese meanings for some example words listed on this web site are based on the site.
[8] http://www.etymonline.com
The site provides good history for a word. Derivation of meanings for some example words is based on the web site.
[9] http://www.thefreedictionary.com/
The web site provides meanings for some example words which are not available in http://www.merriam-webster.com/
[10] http://en.wiktionary.org/
The web site provides meanings for some example words which are not available in http://www.merriam-webster.com/ and in http://www.thefreedictionary.com/
[11] http://www.ldoceonline.com/
The web site provides some usages for some example words on this module on this web site. Unfortunately http://www.ldoceonline.com/ (Longman Dictionary of Contemporary English) does not provide a history or etymology for a word, so it does not reveal the true meaning of an English word.
For example, for the word confuse, the explanation in Longman Dictionary of Contemporary English is:
'confuse: to make someone feel that they cannot think clearly or do not understand: I understand the text but the diagrams are confusing me.'
It does not give you the true meaning:
mix one thing together with another thing.
So this dictionary fails to explain why preposition 'with' should be used with verb 'confuse'.
If you refer to dictionary http://www.merriam-webster.com/, you will immediately know that the preposition 'with' should be used with confuse because confuse means mix up (and because preposition 'with' should be used with verb 'mix').
The dictionary requires a minimum vocabulary for a foreigner to get the meaning of a word, however, it creates an illusion that the explanation or derivation of English words can be built from only 2000 simple English words.
[12] Word Power Made Easy by Norman Lewis, available from http://amazon.com
You can find all important word roots listed in this book on this web site.