@ARTICLE{kennedy89,
    author = {Kennedy, B. W. and Schaeffer, L. R.},
     pages = {1946--1955},
     title = {Genetic evaluation under an animal model when identical genotypes are represented in a population},
   journal = {J. Anim. Sci.},
    volume = {67},
      year = {1989}
}

@ARTICLE{oikawa2009,
    author = {Oikawa, T. and Yasuda, K.},
     title = {Inclusion of genetically identical animals to a numerator relationship matrix and modification of its inverse},
   journal = {Genetics Selection Evolution},
    volume = {41},
    number = {1},
      year = {2009},
     pages = {25},
      doi  = {10.1186/1297-9686-41-25},

}