Willis, D. (1998). Collins COBUILD Student's Grammar: Classroom Edition (Classroom ed.). HarperCollins Publishers.
Chicago-čujuhus (17. p.)Willis, Dave. Collins COBUILD Student's Grammar: Classroom Edition. Classroom ed. London: HarperCollins Publishers, 1998.
MLA-čujuhus (9. p.)Willis, Dave. Collins COBUILD Student's Grammar: Classroom Edition. Classroom ed. HarperCollins Publishers, 1998.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.