(strict sense) The variety of Old Low Franconian that was spoken in Limburg and the Rhineland
2013, Ann Marynissen, Guy Janssens, A regional history of Dutch, in: Frans Hinskens, Johan Taeldeman (eds.), Language and Space: An International Handbook of Linguistic Variation: Volume 3: Dutch (= HSK 30.3), here p. 84:
Old Low Franconian has come down to us in an eastern and a western variety. The most important surviving text in Old East Low Franconian is a translation of Latin psalms, the so-called Wachtendonckse psalmen, written in the tenth century by a monk who lived in the region between Venlo and Krefeld.
2015, Oliver M. Traxel, Languages, in: Albrecht Classen (ed.), Handbook of Medieval Culture: Fundamental Aspects and Conditions of the European Middle Ages: Volume 2, here p. 810:
The surviving texts are dated mainly to the tenth, eleventh and twelfth centuries and are usually divided into two major dialects: Old West Low Franconian, spoken in Flanders, Brabant, and Holland, and Old East Low Franconian, spoken in Limburg and the Rhineland.
2011, Robert S.P. Beekes, revised and corrected by Michiel de Vaan, Comparative Indo-European Linguistics: An Introduction, 2nd ed., p. 29:
In the Netherlands, Low Franconian was spoken along with Frisian and Saxon. A division can be made between Old East and Old West Low Franconian (of which almost nothing is left).
2011, Dominique T. Hoche, Charlemagne, in: Lister M. Matheson (ed.), Icons of the Middle Ages: Rulers, Writers, Rebels, and Saints, here p. 146:
If we went to Liège around the year 750, we would hear Old East Low Franconian in the city, north and northwest; Old Ripuarian Franconian to the east and in Aachen; [...]
