P-ISSN 0008-0845
E-ISSN 2160-8091
Vol. 14, Issue 6, 1960June 01, 1960 PDT 
ccby-nc-nd-4.0 
Walnut orchards on volcanic soils deficient in phosphorus 
Walnut orchards on volcanic soils deficient in phosphorus
E Serr, 
Serr, E. 1960. “Walnut Orchards on Volcanic Soils Deficient in Phosphorus.” California Agriculture 14 (6): 6–7.