@misc
{TN_libero_mab2,
author = {
Schumann, Robert
Schumann, Clara
},
title = {
Robert Schumann's Werke
},
edition = {
Serien-Ausg.
}
,
publisher = {Breitkopf & Härtel},
year = {19XX-},
address = {
Leipzig
},
url = {
http://slubdd.de/katalog?TN_libero_mab2
}
}