Open J. Discrete Math. Vol.10 No.4, October 27, 2020 DOI:10.4236/ojdm.2020.104010
Open J. Discrete Math. Vol.10 No.4, September 16, 2020 DOI:10.4236/ojdm.2020.104009
Open J. Discrete Math. [ISSUE], [PUBDATE] DOI:[DOI]