The orientation number of two complete graphs with linkages. - Khee Meng Koh; Kah Loon Ng (Discret. Math., 2005)

On optimal orientation of cycle vertex multiplications. - Kah Loon Ng; Khee Meng Koh (Discret. Math., 2005)

A generalization of the firefighter problem on Z×Z. - Kah Loon Ng; P. Raff (Discret. Appl. Math., 2008)

On a conjecture concerning the orientation number of a graph. - Kah Loon Ng (Discret. Math., 2009)