König Enzio. Libretto. German. Public domain libretto, Library of Congress

von A.B. Dulk ; Musik von J.J. Abert. (statement of responsibility)
U.S. RISM Libretto Project.
Opera also exists in a later version entitled Enzio von Hohenstarefen--Musikin Geschichte und Gegenwart.
"Als Manuscript gedruckt"--title page; lines marked out--p. 390.
Singers' names not given.