APA
Holden J. H. W., Williams J. T. & International Board for Plant Genetic Resources. (1984). Crop genetic resources. LOndon: Allen & Unwin.
Chicago
Holden J H W, Williams John Trevor and International Board for Plant Genetic Resources. 1984. Crop genetic resources. LOndon: Allen & Unwin.
Harvard
Holden J. H. W., Williams J. T. and International Board for Plant Genetic Resources. (1984). Crop genetic resources. LOndon: Allen & Unwin.
MLA
Holden J H W, Williams John Trevor and International Board for Plant Genetic Resources. Crop genetic resources. LOndon: Allen & Unwin. 1984.