Packing Trominoes is NP-Complete, #P-Complete and ASP-Complete. - Takashi Horiyama; Takehiro Ito; Keita Nakatsuka; Akira Suzuki 001; Ryuhei Uehara (CCCG, 2012)

Complexity of Tiling a Polygon with Trominoes or Bars. - Takashi Horiyama; Takehiro Ito; Keita Nakatsuka; Akira Suzuki 001; Ryuhei Uehara (Discret. Comput. Geom., 2017)