Woldemar Voigt (1910). Lehrbuch der kristallphysik. [S.l.]: Teubner, Leipzig. Consultado em 20 de abril de 2018
doi.org
dx.doi.org
Maher Moakher (2009). «The Algebra of Fourth-Order Tensors with Application to Diffusion MRI». Visualization and Processing of Tensor Fields. [S.l.]: Springer Berlin Heidelberg. pp. 57–80. doi:10.1007/978-3-540-88378-4_4