1."HUMMEL The complete collector's guide and illustrated reference"
By Robert L. Miller & Eric Ehrmann
Pb. Portfolio Press Corporation / 1979 edit. , & 1976 edit.
ISBN: both n.a.
2."Price Guide to M.I. Hummel" Figurines, Plates, more...
By Robert L. Miller ISBN 0-942620-11-9
Pb. Portfolio Press Corporation / 1987 edit.
ISBN 0-942620-11-9
3."M.I. Hummel" The Golden Anniversary Album
by Robert L. Miller & Eric Ehrmann
Photo. by Walter Pfeiffer, & Schecter Lee
Pb. Portfolio Press Corporation / 1989 edit.
ISBN: 0-88365-745-7
4."In the Land of Hummel" Traditional Bavarian life
by Kathleen Saal photo. by Walter Pfeiffer
Robert Campbell Rowe Book
Pb. Portfolio Press Corporation / 1999 edit.
ISBN: 0-942620-28-3