The Calatrava Cross is regarded as trademark of the watches made by Patek Philippe, each of which has it mapped to the crown. The 1932 presented model Calatrava was named after an order of knights founded by the abbot Raimondo in the city of Calatrava in 1158.

• Das große Uhrenlexikon; Author Fritz von Osterhausen; ISBN 3898804305
• Patek Philippe, Geneve; Authors Martin Huber, Alan Banbery; ISBN 3906500012
• Patek Philippe. Komplizierte Armbanduhren; Authors Giampiero Negretti, Paolo DeVecchi; ISBN 382901449X