1. Eschenbach, C.A. (1987) Eigenvalue Classification in Qualitative Matrix Analysis. Clemson University, South Caroli-na.
2. Algebraically positive matrices
3. On Sign Pattern Matrices that Allow or Require Algebraic Positivity
4. On some sign patterns of algebraically positive matrices
5. Das, S. (2021) Classifications of Some Algebraically Positive, Di-agonalizable and Stable Matrices with Their Sign Patterns. Department of Mathematics Indian Institute of Technology, Guwahati.