The Concise Oxford English Dictionary was first published in 1911. It was designed as a shorter version of the Oxford English Dictionary, providing definitions and explanations in a more compact format.

The Oxford English Dictionary Is considered to have every word in the English language. There is only one. Whereas a normal dictionary is much more concise.

triennium (concise oxford English dictionary)

Oxford Dictionary of English was created in 1998.

Oxford English Dictionary was created in 1989.