Đọc thêm Nhóm_ngôn_ngữ_Anh-Frisia

  • Friedrich Maurer (1942), Nordgermanen und Alemannen: Studien zur Sprachgeschichte, Stammes- und Volkskunde, Strasbourg: Hünenburg.
  • Wolfram Euler (2013), Das Westgermanische [subtitle missing] (West Germanic: from its Emergence in the 3rd up until its Dissolution in the 7th Century CE: Analyses and Reconstruction). 244 p., in German with English summary, Verlag Inspiration Un Ltd., London/Berlin, ISBN 978-3-9812110-7-8.
  • Ringe, Donald R. and Taylor, Ann (2014). The Development of Old English - A Linguistic History of English, vol. II, 632p. ISBN 978-0199207848. Oxford.