Recognition of diseases and pests of farm crops /
Gram, Ernst.
Bovien, Prosper.
Stapel, Chr.
Frederiksen, Ingebord.
Olsen, Ellen.
London Blandford P
1969
Preface and captions in Danish, English, and Swedish
Previous ed. (B59-1940), Copenhagen: Danish Agricultural Information and Advisory Aids Service; Cambridge: Heffer, 1958
Field crops