APA
Humphreys L. R., . (1997). The evolving science of grassland improvement. Cambridge: Cambridge University Press.
Chicago
Humphreys L R, . 1997. The evolving science of grassland improvement. Cambridge: Cambridge University Press.
Harvard
Humphreys L. R., . (1997). The evolving science of grassland improvement. Cambridge: Cambridge University Press.
MLA
Humphreys L R, . The evolving science of grassland improvement. Cambridge: Cambridge University Press. 1997.