An O(n½+∑)-Space and Polynomial-Time Algorithm for Directed Planar Reachability. - Tatsuya Imai; Kotaro Nakagawa; Aduri Pavan; N. V. Vinodchandran; Osamu Watanabe 001 (CCC, 2013)

The First Eigenvalue of (c, d)-Regular Graph. - Kotaro Nakagawa; Hiroki Yamaguchi (IEICE Trans. Inf. Syst., 2013)

Õ(√n)-Space and Polynomial-Time Algorithm for Planar Directed Graph Reachability. - Tetsuo Asano; David G. Kirkpatrick; Kotaro Nakagawa; Osamu Watanabe 001 (MFCS (2), 2014)

O(sqrt(n))-Space and Polynomial-time Algorithm for the Planar Directed Graph Reachability Problem. - Tetsuo Asano; David G. Kirkpatrick; Kotaro Nakagawa; Osamu Watanabe 001 (Electron. Colloquium Comput. Complex., 2014)

O (n^{1/3})-Space Algorithm for the Grid Graph Reachability Problem. - Ryo Ashida; Kotaro Nakagawa (SoCG, 2018)

O͂(n1/3)-Space Algorithm for the Grid Graph Reachability Problem. - Ryo Ashida; Kotaro Nakagawa (CoRR, 2018)

A Sublinear-space and Polynomial-time Separator Algorithm for Planar Graphs. - Ryo Ashida; Tatsuya Imai; Kotaro Nakagawa; A. Pavan 001; N. V. Vinodchandran; Osamu Watanabe 001 (Electron. Colloquium Comput. Complex., 2019)