↑ Ha, Thu-Huong. "Germany has ended a century-long debate over a missing letter in its alphabet" (in English). สืบค้นเมื่อ 5 December 2017. According to the council’s 2017 spelling manual: When writing the uppercase [of ß], write SS. It’s also possible to use the uppercase ẞ. Example: Straße — STRASSE — STRAẞE.CS1 maint: Unrecognized language (link)
↑ For a history of the German consonants see Fausto Cercignani. The Consonants of German: Synchrony and Diachrony. Milano: Cisalpino, 1979. ISBN 8820501856.
↑ Barbour, Stephen; Stevenson, Patrick (1990). Variation in German. Cambridge: Cambridge University Press. pp. 160–163. ISBN978-0-521-35704-3.
