Arnold, H.J.P., author
Dufour Editions, 1966
Buku Teks
Dixon, Chris J., author
Routledge, 2015
Buku Teks
by H.B. Chenery ... [et al.]
Universitaire Pers Rotterdam, 1967
Buku Teks
Bennett, Olivia, author
Palgrave Macmillan, 2012
Buku Teks
Carlson, Sune, author
Svenska Bokforlaget, 1964
Buku Teks