diff --git a/references.bib b/references.bib
index ba8fbe3..3fb3de7 100644
--- a/references.bib
+++ b/references.bib
@@ -23,6 +23,12 @@ @book{vonhagen1944
   year           = {1944}
 }
 
+@book{thompson1962catalog,
+  author         = {Thompson, John Eric Sidney},
+  title          = {A Catalog Of Maya Hieroglyphs},
+  year           = {1962}
+}
+
 @book{thompson1962,
   author         = {Thompson, John Eric Sidney},
   publisher      = {Norman : University of Oklahoma Press},
@@ -39,6 +45,14 @@ @book{knorozov1967
   series         = {Russian translation series of the Peabody Museum of Archaeology and Ethnology},
 }
 
+@book{crystal2010,
+  author         = {Crystal, David},
+  title          = {The Cambridge Encyclopedia of Language},
+  publisher      = {Cambridge University Press, Cambridge},
+  year           = {2010},
+  edition        = {3},
+}
+
 @book{estrada-belli2011,
   author         = {Estrada-Belli, Francisco},
   title          = {The First Maya Civilization : Ritual and Power Before the Classic Period},