TY  - BOOK
AU  - Yag,Otto; Bash,John K.
TI  - The pre-stamp postal markings of Mexico
CY  - Elmhurst, Ill.
PB  - Elmhurst Philatelic Society International
KW  - Cancellations (Philately)--Mexico
KW  - Postmarks--Mexico--Catalogs
ER  -