The Core Historical Literature of Agriculture (CHLA) is a core electronic collection of agricultural texts published between the early nineteenth century and the middle to late twentieth century. Full-text materials cover agricultural economics, agricultural engineering, animal science, crops and their protection, food science,forestry, human nutrition, rural sociology, and soil science. Scholars have selected the titles in this collection for their historical importance. Their evaluations and 4,500 core titles are detailed in the seven volume series The Literature of the Agricultural Sciences, Wallace C. Olsen, series editor.