Regular fuzzy matrices and fuzzy equations. - Han Hyuk Cho (Fuzzy Sets Syst., 1999)

The m-step competition graph of a digraph. - Han Hyuk Cho; Suh-Ryung Kim; Yunsun Nam (Discret. Appl. Math., 2000)

Domination graphs of regular tournaments. - Han Hyuk Cho; Suh-Ryung Kim; J. Richard Lundgren (Discret. Math., 2002)

On The Trees Whose 2-Step Competition Numbers Are Two. - Han Hyuk Cho; Suh-Ryung Kim; Yunsun Nam (Ars Comb., 2005)

A class of acyclic digraphs with interval competition graphs. - Han Hyuk Cho; Suh-Ryung Kim (Discret. Appl. Math., 2005)

The competition number of a graph having exactly one hole. - Han Hyuk Cho; Suh-Ryung Kim (Discret. Math., 2005)

On the graph inequality thetaE(G) geq thetaE(Gm). - Han Hyuk Cho; Suh-Ryung Kim; Jung Yeun Lee (Discret. Math., 2006)