THESE LINKS ARE SPECIFIC TO IRELAND
The Belfast Forum : http://www.belfastforum.co.uk /In particular on this Crawfords with special thanks to "CMcG" http://www.belfastforum.co.uk/index.php/topic,82018.msg2248436.html#msg2248436
Christian Science, an American Religion in Britain. 1895 - 1940
Claire F. Gartrell-Mills. Wolfson College, Oxford University, 1991.
The Crawfords of Donegal and How they Came There. This is an old publication (1897) that is now available online. I cannot find specific reference to our Crawfords, but it seems to support the supposition that Crawfords were originally from Ayrshire in Scotland encouraged to Ireland as a later wave of plantation.
http://file:///C:/Users/Jeremyhw/Documents/Family%20Tree/Crawford/crawfords.pdf
Fitzroy Avenue, Belfast. Our Crawfords lived in this street, now university accommodation. That house still stands. This online publication explains the origins of the street's name and the changes to the street over time.
The Flax Industry in Northern Ireland 20 years on. P. C. Elwood, I.R.McAulay, J. H. Elwood.
https://www.sciencedirect.com/science/article/pii/S0140673682922899
The flax industry and associated illnesses.
https://www.sciencedirect.com/science/article/pii/S0140673682922899
The Ulster Scots and the Ulster Plantation.
http://www.ulsterancestry.com/ulster-scots-2.html
Ireland in the Nineteenth Century
https://www.historylearningsite.co.uk/ireland-1845-to-1922/ireland-in-the-nineteenth-century/
The Ulster Covenant
https://www.nidirect.gov.uk/services/search-ulster-covenant
1895 - 1940
1921 - 1925: The Irish Civil War and Stabilisation of Northern Ireland
http://www.wesleyjohnston.com/users/ireland/past/history/19211925.html