[5] Madarkar J, Sharma P, Singh R P. Sparse representation for face recognition: a review paper[J]. IET Image Processing, 2021, 15(9), 1825-1844.
[6] Ergin S, Isik S, Gulmezoglu M B. Face recognition by using 2d orthogonal subspace projections[J]. Traitement du Signal, 2021, 38(1), 51-60.