Raymond Hickey, Researching Northern English (2015)
Katie Wales, Northern English: A Social and Cultural History (2009)
Dick Lloyd, Northern English: Phonetics, Grammar, Texts (2015)
Sali A. Tagliamonte, Roots of English. Exploring the History of Dialects (2012) (mainly northern)
Perspectives on Northern Englishes (2017)
Joan Beal, English dialects in the North of England: phonology (book chapter, 2004)
Stuart Maconie, Are northern English accents dying out? Are they eck as like (newspaper article, 2021)
18 Slang Expressions in Northern English (and How To Use Them) (web page, 2018)
Wikipedia: English Language in Northern England
John Trotter Brockett, A Glossary of North Country Words (1829)
Durham
John Bailey, County Durham Words – 1810
Lancashire
Fred Holcroft, Lancashire English (1997)
George Hull, A Glossary of Lancashire Dialect (webpage, 2013)
Dave Dutton, Lanky Spoken Here! (1978)
Harry & Lesley Boardman, Folk Songs & Ballads of Lancashire (1973)
Merseyside and Liverpool
Tony Crowley, Scouse: A Social and Cultural History (2012)
Kevin Watson, Liverpool English (Journal of the International Phonetic Association, 2007)
Northumberland
Richard Oliver Heslop, Northumbrian Words (1892-94)
Glossary of Northumbrian Dialect Words (webpage)
Northumbrian Language Society (website)
Wikipedia: Northumbrian dialect
Tyneside & Newcastle
Karsten Keuchler, Geordie Accent and Tyneside English (seminar paper, 2007; pub. 2010)
Yorkshire
The Yorkshire Historical Dictionary. A Glossary of Yorkshire Words, 1120-c.1900 (2021)
Yorkshire Historical Dictionary (University of York website)
Samuel Dyer, Dialect of the West Riding of Yorkshire: a short history of Leeds and other towns (1891)
Yorkshire Sayings, Phrases and Expressions and what they mean (2022)
Yorkshire Dialect and Slang - List