Thomas L. Muller: Sulfuric Acid and Sulfur Trioxide, Kirk-Othmer Encyclopedia of Chemical Technology, John Wiley & Sons, New York, 2001 Teoksen verkkoversio Viitattu 28.2.2011
Hermann Müller: Sulfuric Acid and Sulfur Trioxide, Ullmann's Encyclopedia of Industrial Chemistry, John Wiley & Sons, New York, 2002 Teoksen verkkoversio Viitattu 28.2.2011
Gregory P. Dado, Edward A. Knaggs & Marshall J. Nepras: Sulfonation and Sulfation, Kirk-Othmer Encyclopedia of Chemical Technology, John Wiley & Sons, New York, 2001 Teoksen verkkoversio Viitattu 28.2.2011
