I was just searching for last names of my ancestors on the FamilySearch’s Family History Books and came across Ramos/Cuellar : from Pedro Eufracio Ramos & Bartolome Cuellar of Nuevo Leon to Julia Ramos Cantu of Texas, c. 1650-1983 by Richard Cristobal Hernandes jr. and Mark A. Phillips. Turned out to be an excellent book very well researched. This book contains alot of information not just on the Ramos and Cuellar from Ciudad Mier and Revilla/Ciudad Guerrero Tamaulipas Mexico but also on many other people from the same area.
The author did an excellent job with the family trees and family group sheets. This work helped me fill in many gaps in my research and it is a very good read. It also includes alot of history of the area.
If your interest is in this area and or last names are Ramos or Cuellar then I highly recommend that you download your copy and read it, you can thank me later.