Alguacil, F. J. 1999. “Study of the Structure of H2SO4-Amine Primene 81R and Fe(III)-Amine Primene 81R Sulphate Compounds by Infrared Spectroscopy”. Revista De Metalurgia 35 (4):249-54. https://doi.org/10.3989/revmetalm.1999.v35.i4.631.