Programming Assistant System Using Improved Flowchart for the Visually Impaired. - Ryo Hirakawa; Rin Hirakawa; Hideaki Kawano; Kenichi Nakashi; Yoshihisa Nakatoh (IHIET, 2019)

Counting Lyndon Subsequences. - Ryo Hirakawa; Yuto Nakashima 001; Shunsuke Inenaga; Masayuki Takeda (Stringology, 2021)