P. Harper
发表
P. Harper,
1978
.
P. Harper,
1978
.
J. Jehl,
M. M. Boyd,
R. Schlatter,
1991
.
P. Harper,
1983
.
P. Harper,
1976
.
C. Townsend,
P. Davis,
I. Hedge,
1972
.
P. Harper,
H. Will,
1968,
European Potato Journal.
D. Graham,
P. Harper,
A. Boyd,
1963
.