The Terwilliger algebras of certain association schemes over the Galois rings of characteristic 4. - Haruo Ishibashi (Graphs Comb., 1996)

Terwilliger Algebras of Cyclotomic Schemes and Jacobi Sums. - Haruo Ishibashi; Tatsuro Ito; Mieko Yamada (Eur. J. Comb., 1999)