A new M-matrix of Type III, its properties and applications
  Some binary matrices like (1,-1) and (1,0) were studied by many authors like Cohn, Wang, Ehlich and Ehlich and Zeller, and Mohan, Kageyama, Lee, and Gao. In this recent paper by Mohan et al considered the M-matrices of Type I and II by studying some of their properties and applications. In the present paper they discussed the M-matrices of Type III, and studied their properties and applications. They gave some constructions of SPBIB designs and some corresponding M-graphs, which are being constructed by it. This is the continuation of our earlier research work in this direction, and these papers establish the importance of non-orthogonal matrices as well. 
R.N.Mohan, Moon Ho Lee, and Ram Paudal