WASET
    Ber-Lin Yu and  Ting-Zhu Huang,  A Note on the Minimum Cardinality of Critical Sets of Inertias for Irreducible Zero-nonzero Patterns of Order 4.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    January 2010, vol. 37(1). 142 - 144
    [viewed 25 April 2024]. Available from: https://publications.waset.org/pdf/10461.