“…Some of them are the Thomas projective parameter, the Weyl projective tensor, the Weyl conformal curvature, and many others. These invariants may be found in the next monographs, books and papers: Mikeš [1,2,[8][9][10][11], Sinyukov [16], Hinterleitner [10], Berezovski [1,2,10], etc.…”