@book{wiener+monumental+bauten+abth+1+das+k+k+hof+opernhaus+in+wien,
    author = {Nüll, Eduard van der i Siccard von Siccardsburg, August},
    title = {Wiener Monumental-Bauten. Abth. 1, Das K. K. Hof-Opernhaus in Wien},
    address = {Wien},
    publisher = {Ad. Lehmann},
    date = {1885}
}