A Short Proof of a Result of Pollak on Steiner Minimal Trees. - Ding-Zhu Du; E. Y. Yao; Frank K. Hwang (J. Comb. Theory A, 1982)

The Steiner Ratio Conjecture Is True for Five Points. - Ding-Zhu Du; Frank K. Hwang; E. Y. Yao (J. Comb. Theory A, 1985)