Harpen, N. H. v., & Watkins, S. J. (1930). The electrometric determination of the hydrogen ion concentration in the latex of Hevea brasiliensis and its applicability to technical problems. Varekamp & Co.
Chicago-referens (17:e uppl.)Harpen, Nicolaas Hendrik van, och S. J. Watkins. The Electrometric Determination of the Hydrogen Ion Concentration in the Latex of Hevea Brasiliensis and Its Applicability to Technical Problems. Medan: Varekamp & Co, 1930.
MLA-referens (8:e uppl.)Harpen, Nicolaas Hendrik van, och S. J. Watkins. The Electrometric Determination of the Hydrogen Ion Concentration in the Latex of Hevea Brasiliensis and Its Applicability to Technical Problems. Varekamp & Co, 1930.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.