41
42
by Bulmer, J.
Published 1992
43
44
by Rossister,John R.
Published 1987
45
by Lovelock, Christopher H.
Published 1996
46
by Lancaster, Geoff
Published 1994
47
by Bednell, Schiffman
Published 1997
48
Published 1986
49
by Boone, Louis E.
Published 1989
50
by Pride, William M.
Published 2003
51
by Armstrong, Gary
Published 2002
52
by Lovelock, Christopher H.
Published 2002
53
by Roll, Graham
Published 2001
54
by Kotler, Philip
Published 2004
55
by Hill, Elizabeth
Published 1999
56
57
by Jobber, David,
Published 2004
58
by Evans, Joel R.
Published 1987
59
by Kotler, Philip
Published 1986
60
Published 1980