Northern Popoloca is an indigenous language of Puebla state, Mexico. The dialects of the two towns where it is spoken, San Luís Temalacayuca (a.k.a. Temalacayuca, San Luís) and San Marcos Tlacoyalco (a.k.a. Tlacoyalco, San Marcos), are over 90% mutually intelligible.
^Machin, Polly; Stark, Sharon (1977). Stress and tone in Tlacoyalco Popoloca. Dallas: Summer Institute of Linguistics and the University of Texas at Arlington.{{cite book}}: CS1 maint: publisher location (link)
^Stark C., Sara (2014). Los pronombres en ngigua. SIL-Mexico Electronic Working Papers, 12a.: SIL International.{{cite book}}: CS1 maint: location (link)