Music by Ernst - Nachtwächter. Libretto. German Opera

nach dem gleichnamigen Lustspiel von Körner ; Text und Musik von Ernst Netrok. (statement of responsibility)
U.S. RISM Libretto Project.
Price on front cover: 30 Pf.; publisher's lists--p. [1] at end and on back cover.
Performers' names not given.
Der Nachtwächter, with music by Ernst Korten, first performed in Elberfeld in 1896--Gruber. Opern-Uraufführungen.
Netrok presumably a pseudonym for (as it is a retrograde spelling of) Korten.