Anthony John Downs, (1993), Chemistry of Aluminium, Gallium, Indium, and Thallium, Springer, ISBN 978-0-7514-0103-5 /wiki/ISBN_(identifier)
Crystal Structure of a new mineral söhngeite, J.D. Scott, The American Mineralogist, (1971), 56, 355
Anthony John Downs, (1993), Chemistry of Aluminium, Gallium, Indium, and Thallium, Springer, ISBN 978-0-7514-0103-5 /wiki/ISBN_(identifier)