CHAPTER II.
The Wheat Problem, by Sir W. Crookes. (John Murray, 1899.)
The Production of Wheat in the British Empire, by A. E. Humphries. (Journal of the Royal Society of Arts, Vol. LVII, p. 229.)
Wheat Growing in Canada, the United States, and the Argentine, by W. P. Rutter. (Adam and Charles Black, 1911.)
Agricultural Note-Book, by Primrose McConnell. (Crosby, Lockwood and Son, 1910.)