Tracy, H. (1963). The first day of friday. Random House.
Cita Chicago Style (17a ed.)Tracy, Honor. The First Day of Friday. New York, Estados Unidos: Random House, 1963.
Cita MLA (9a ed.)Tracy, Honor. The First Day of Friday. Random House, 1963.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.