Cita APA (7a ed.)
Dixson, R. J. Modern American English: Workbook.
Cita estilo Chicago (17a ed.)
Dixson, Robert J. Modern American English: Workbook.
Cita MLA (9a ed.)
Dixson, Robert J. Modern American English: Workbook.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.