• Follansbee, N. 1987. The Ejercito Issue. MEXICANA. 36(4): 8-11. HE6187.M612
  • Follansbee, N. 1996. The Stamps of the Mexican Revolution 1913-1916. Collectors Club of Chicago, Chicago, Ill. HE6185.M6F65 1996
  • Hamilton, C.S. 1921. White and Green Seals of Sonora – The Gems of the 20th Century. Stamp Collectors Fortnightly. No. 70. HE6187.S7815
  • Hinojosa, C. 1917. A Brief History of the Mexican Postage Stamps during the Revolutionary Period, 1913-1917. Imprenta Franco-Mexicana, S.A. Mexico. HE6185.M6H66 1917
  • Irwin, H. 1971. The White and Green Seals of Sonora, Mexico. Mexico Elmhurst Philatelic Society international, as a supplement to MEXICANA.
  • Linn, G.W. 1916. The White and Green Seal Issues of Sonora. W. M. Linn & Sons Company. HE6185.M6S6X 1916
  • Linn, G. W. 1917. The War Stamps of Mexico. George W. Linn, Co. HE6185.M6L75 1917
  • Mekell, C. H. Sonora (Mexico) Postage stamps. Philatelic Journal of America. 26(6): 2001-209. HE6187.P54454
  • Phillips, Charles J. 1916. The Civil War Stamps of Mexico 1913-1916. London Philatelist. (various issues), 154-300. HE6187.L847
  • Tittmann, A.O. Sonora, 20th Century “Post Office Mauritius.” American Philatelist. 1951. 64(4):307-313. HE6187.A6X

Auction Catalogs cited in this finding guide:

  • H.R. Harmer, Eleventh Sale, June 24-27, 1935: The Arthur Hind Collection of Central and South America.
  • Mid Atlantic Stamp Sales, H. A. Robinette, Sale 24, April 4 -5, 1947: The Col. C.S. Hamilton Collection.
  • Robson Lowe, Inc., June 5, 1948: The E.M. Taylor Collection of Mexico.