editors, Sue Moorhead, Elizabeth Swanson, Marion Johnson, Meridean L. Maas
Elsevier, 2018
Buku Teks SO
Waterworth, Derek
Basingstoke Macmillan ., 1987
Buku Teks SO
Brewer, Derek
Longman, 1984
Buku Teks SO
Osbourn, Derek
Mit chell, 1991
Buku Teks SO
Osbourn, Derek
Mitchell's, 1989
Buku Teks SO