Breaking the ideological barrier
Artikel Jurnal
Tokos, Sherry
Breaking the age barrier
Viking Canada, 2003
Buku Teks SO
Dark, Eleanor, 1901-
No barrier
Collins, 1966
Buku Teks SO
Wallace, Catherine
Reading
1992
Buku Teks
Wallace, Catherine
Reading
Oxford University Press, 1993
Buku Teks SO