1. MKL, Intel(R) math kernel library https://software.intel.com/en-us/intel-mkl.
2. S. Tomov, R. Nath, P. Du, J. Dongarra, Magma, matrix algebra on GPU and multicore architectures http://icl.cs.utk.edu/magma/.
3. G. Guennebaud, B. Jacob, et al., Eigen v3, 2016, http://eigen.tuxfamily.org/.
4. Real-time covariance tracking algorithm for embedded systems;y Terán,2013
5. Application of Kalman filtering to track and vertex fitting;Frühwirth;Nucl. Instrum. Methods Phys. Res., Sect. A,1987