Alternate forms for the umlaut vowels for the written form of <a href="//commons.wikimedia.org/wiki/Volap%C3%BCk" title="Volapük">Volapük</a>, proposed by <a href="//commons.wikimedia.org/wiki/Johann_Martin_Schleyer" class="mw-redirect" title="Johann Martin Schleyer">Johann Martin Schleyer</a>; they were rarely used.
Supersedes <a href="//commons.wikimedia.org/wiki/File:VolapukAOU.png" title="File:VolapukAOU.png">File:VolapukAOU.png</a>.
Unknown typographer
Die Kunst die internationale Verkehrssprache „VOLAPÜK“ schnell zu erlernen, Julius Lott, A. Hartleben's Verlag, Wien. (1888)