Cita APA (7a ed.)
Ewing, G. M. Calculus of Varitions with Applications. Dover.
Cita estilo Chicago (17a ed.)
Ewing, George M. Calculus of Varitions with Applications. Nueva York, EUA: Dover.
Cita MLA (9a ed.)
Ewing, George M. Calculus of Varitions with Applications. Dover.
Precaución: Estas citas no son 100% exactas.