Cornelius Tacitus: Germania. Transmitted and explained by Arno Mauersberger. VMA-Verlag, Wiesbaden [1981?], p. 142, DNB-IDN810365324 (Latin, German; licensed edition of Dieterich's publishing house accountant, Leipzig).
Maurits Gysseling: Toponymisch Woordenboek van België, Nederland, Luxemburg, Noord-Frankrijk en West-Duitsland. Ghent 1960, DNB-IDN560536216, p. 956 (kantl.be, Retrieved 5 December 2017; Dutch).
degruyter.com
Heinrich Beck et al. (editor): Reallexikon der Germanischen Altertumskunde. volume 36/37 (register volume 1 and 2): Authors, keywords, subject index, abbreviations, 2nd edition. de Gruyter, Berlin 2008, ISBN978-3-11-019146-2, p. 20 ff.; "PDF; 499 kB"(PDF). Archived from the original(PDF) on 23 September 2013. Retrieved 2013-09-21.. In: degruyter.com, Retrieved 5 December 2017.
kantl.be
bouwstoffen.kantl.be
Maurits Gysseling: Toponymisch Woordenboek van België, Nederland, Luxemburg, Noord-Frankrijk en West-Duitsland. Ghent 1960, DNB-IDN560536216, p. 956 (kantl.be, Retrieved 5 December 2017; Dutch).
tufts.edu
perseus.tufts.edu
L. S.: Visbu´rgii. In: Dictionary of Greek and Roman Geography. 2 volumes. Edited by William Smith. Walton and Maberly, John Murray, London 1854, OCLC1000689106 (perseus.tufts.edu, Retrieved 5 December 2017).
web.archive.org
Heinrich Beck et al. (editor): Reallexikon der Germanischen Altertumskunde. volume 36/37 (register volume 1 and 2): Authors, keywords, subject index, abbreviations, 2nd edition. de Gruyter, Berlin 2008, ISBN978-3-11-019146-2, p. 20 ff.; "PDF; 499 kB"(PDF). Archived from the original(PDF) on 23 September 2013. Retrieved 2013-09-21.. In: degruyter.com, Retrieved 5 December 2017.
worldcat.org
L. S.: Visbu´rgii. In: Dictionary of Greek and Roman Geography. 2 volumes. Edited by William Smith. Walton and Maberly, John Murray, London 1854, OCLC1000689106 (perseus.tufts.edu, Retrieved 5 December 2017).