Martins, E. P., Amos, E., & Pasqualin, E. (1992). Graded english (2.ed.). Moderna Hamburg.
Cita Chicago Style (17a ed.)Martins, Elisabeth Prescher, Eduardo Amos, y Ernesto Pasqualin. Graded English. 2.ed. São Paulo, SP: Moderna Hamburg, 1992.
Cita MLA (9a ed.)Martins, Elisabeth Prescher, et al. Graded English. 2.ed. Moderna Hamburg, 1992.
Precaución: Estas citas no son 100% exactas.