Si una citación bibliográfica es proporcionada como fuente de una cita, las dos se
pueden agrupar usando el elemento <CIT>
Ejemplo
Lexicography has shown little sign of being affected by the work of followers of J.R. Firth, probably best summarized in his slogan, <quote>You shall know a word by the company it keeps</quote> <ref>(Firth, 1957)</ref>