Hummel-Book by the Late Berta HummelMargarete 1893-1949 Seemann, Maria Innocentia 1909-1946 Hummel · First published 2021Open the Tome
Warman's Hummel field guideCarl F. Luckey, Dean A. Genth, Maria Innocentia Hummel · First published 2004Open the Tome
Berta HummelBerta Hummel, Maria Innocentia Hummel, Berta Hummel Museum, Genoveva Nitz · First published 2002 · Latest edition 2003Open the Tome
