Association of American... www.amazon.com

The Association of American... www.science.org

The Association of American... www.science.org

AGNR History | College of... agnr.umd.edu

Forty-Third Annual Report,... nmsu.contentdm.oclc.org

Bibliography of the... exploreuk.uky.edu

Arkansas Agricultural... www.facebook.com

NH Agricultural Experiment... colsa.unh.edu

Bibliography of the... exploreuk.uky.edu

Research & Experiment... agsci.oregonstate.edu

State Agricultural... www.nifa.usda.gov

Mass. Agricultural... ag.umass.edu

Alabama Agricultural... encyclopediaofalabama.org

Utah Historical Quarterly,... issuu.com

Bulletin (United States.... archive.org

The History of the Copper... www.copperriverrecord.net

Bulletin (United States.... archive.org

Agricultural Experiment... agsci.psu.edu

NH Agricultural Experiment... colsa.unh.edu

Arthur H. Post Agronomy... agresearch.montana.edu