Muzychuk I A

Publications in Math-Net.Ru

1. On the nonexistence of 4-critical graphs of twelfth order
   
   Diskr. Mat., 4:2 (1992),  99–114
2. On the nonexistence of even 4-critical graphs of order 12
   
   Diskr. Mat., 2:4 (1990),  47–59
3. Nonexistence of some twelfth-order $4$-critical graphs
   
   Vestnik Moskov. Univ. Ser. 1. Mat. Mekh., 1989, no. 6,  58–60