P-ISSN 0008-0845
E-ISSN 2160-8091
Vol. 18, Issue 4, 1964April 01, 1964 PDT 
ccby-nc-nd-4.0 
Progress in selective harvesting: Lettuce 
Progress in selective harvesting: Lettuce
R Griffin, R Garrett, M Zahara, 
Griffin, R, R Garrett, and M Zahara. 1964. “Progress in Selective Harvesting: Lettuce.” California Agriculture 18 (4): 2–3.