A Comprehensive Grammar of the English Language published (20-5-1985)

This goes back to the Survey of English Usage, begun by Randolph Quirk at UCL in 1959, an attempt to gather real data on both spoken and written contemporary English.
First fruits: A Grammar of Contemporary English (Quirk, Greenbaum, Leech and Svartvik, 1972).
The 1985 work by the same authors, "far more comprensive in scope", and with an index compiled by our own David Crystal.
https://en.wikipedia.org/wiki/A_Comprehensive_Grammar_of_the_English_Language
has a note on a critical review by R.Huddleston, and links to two later grammars with similar ambitions:
Longman Grammar of Spoken and Written English (Biber, Johansson, Leech, Conrad, Finegan, 1999)
Cambridge Grammar of the English Language (Huddleston, Pullum, 2002)