1. Zimmerman A. Botanical Microtechnique, J. E. Humphrey. Henry Holt & Co., New York 1893; 182, See
2. , The stock used was from the laboratory of Prof. B. B. Burlingame of Stanford University; the author has not compared the result with stains from other sources.
3. McClung C. E. Handbook of Microscopical Technique. Paul B. Hoeber Inc., New York 1929; 116–119, See
4. , The hematoxylin employed in this later work was of American manufacture. certification No. F H 4 b.
5. McClung C. E. Handbook of Microscopical Technique. 469