Christopherson, P. (1975). An advance English Grammer. Macmillan.
Chicago-čujuhus (17. p.)Christopherson, P. An Advance English Grammer. London: Macmillan, 1975.
MLA-čujuhus (9. p.)Christopherson, P. An Advance English Grammer. Macmillan, 1975.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.