Soojin Cho On the Support Size of Null Designs of Finite Ranked Posets. [Citation Graph (0, 0)][DBLP] Combinatorica, 1999, v:19, n:4, pp:589-595 [Journal]
Soojin Cho Minimal Null Designs and a Density Theorem of Posets. [Citation Graph (0, 0)][DBLP] Eur. J. Comb., 1998, v:19, n:4, pp:433-440 [Journal]