Farmers all over Iowa have read about and heard about antibiotics. And many farmers are using them. What are these substances? Where did they come from? How are they produced? Here's their story up to the present time.
Fox, Sidney W.
"What Are Antibiotics?,"
Iowa Farm Science: Vol. 7
, Article 2.
Available at: https://lib.dr.iastate.edu/farmscience/vol7/iss4/2