For additional information about the issued stamps, see Bob Hohertz's on-line collection of Private Die Proprietary stamps.
References:
Butler and Carpenter, Letter Book [eleven volumes].
D'Alessandris, D., "Private Die Proprietary die essays: Match and medicine stamps that almost were, Part I match and canned food essays" The American Revenuer (Vol. 60, No.2) March-April 2006.
---, "Private Die Proprietary die essays: Match and medicine stamps that almost were, Part II medicine, perfume and playing card essays" The American Revenuer (Vol. 60, No.4) July-August 2006.
Friedberg, R. (Undated). Collector’s Handbook For Private Die Proprietary Proofs and Census of the Morton Dean Joyce Collection of These Issues.
Holcombe, H. W., 1979. Patent Medicine Tax Stamps, Lawrence, MA: Quarterman Publications, Inc.
Perry, Elliott, Pat Paragraphs, 1981: Bureau Issues Association, Inc., Springfield, VA.
Toppan, G. L., H. E. Deats and A. Holland. 1899. An Historical Reference List of the Revenue Stamps of the United States. Boston: Boston Philatelic Society. Reprinted as The Boston Revenue Book. Lawrence, MA: Quarterman Publications, 1979.
Turner, G. T. 1974. Essays and Proofs of United States Internal Revenue Stamps: A compilation with relative prices. Arlignton, MA: Bureau Issues Association, Inc.
West, C., 1980 Private Die Match Stamps. Pacific Palisades, CA: Castenholz and Sons
West, C. 1980. United States Match and Medicine Stamps. Pacific Palisades, CA: Castenholz and Sons.