1. C. Bekh-Ochir and D. Riley, On the Grassmann T-space, Journal of Algebra and its Applications 7 (2008), 319–336.
2. A. Belov, No associative PI-algebra coincides with its commutant (Russian), Sibirskiĭ Matematicheskiĭ Zhurnal 44 (2003), 1239–1254; English translation: Siberian Mathematical Journal 44 (2003), 969–980.
3. P. Z. Chiripov and P. N. Siderov, On bases for identities of some varieties of associative algebras (Russian), PLISKA Studia Mathematica Bulgarica 2 (1981), 103–115.
4. J. Colombo and P. Koshlukov, Central polynomials in the matrix algebra of order two, Linear Algebra and its Applications 377 (2004), 53–67.
5. V. Drensky, Free algebras and PI-algebras, Graduate Course in Algebra, Springer, Singapore, 1999.