Cita APA (7a ed.)

Serpa, O. (1962). Modern english grammar (10.ed.). Francisco Alves Paulo de Azevedo.

Cita Chicago Style (17a ed.)

Serpa, Oswaldo. Modern English Grammar. 10.ed. Francisco Alves Paulo de Azevedo, 1962.

Cita MLA (9a ed.)

Serpa, Oswaldo. Modern English Grammar. 10.ed. Francisco Alves Paulo de Azevedo, 1962.