Hardness and Approximation of the Selected-Leaf-Terminal Steiner Tree Problem. - Sun-Yuan Hsieh; Huang-Ming Gao (PDCAT, 2006)

On the Internal Steiner Tree Problem. - Sun-Yuan Hsieh; Huang-Ming Gao; Shih-Cheng Yang (TAMC, 2007)

On the partial terminal Steiner tree problem. - Sun-Yuan Hsieh; Huang-Ming Gao (J. Supercomput., 2007)

The internal Steiner tree problem: Hardness and approximations. - Chao-Wen Huang; Chia-Wei Lee; Huang-Ming Gao; Sun-Yuan Hsieh (J. Complex., 2013)