Coba jelasin Lihat juga dari Volapük dalam bahasa melayu dong

Handbook of Volapük , Charles E. Sprague (1888)

A complete italian grammar of Volapük (1888) by V. Amoretti

Una grammatica completa di Volapük in lingua italiana (1888) a cura di V. Amoretti

A ten-lesson course  in modern Volapük

Flenef bevünetik Volapüka / International Friendship of The World Language

"Arie de Jong's Revision of Volapük (1931)"  by Ed Robertson. From the 21st edition of the Journal of Planned Languages, 1995.

Article on Volapük from the 1911 Encyclopaedia Britannica