Double-walled carbon nanotubes fabricated by a hydrogen arc discharge method - Hutchison, J; Kiselev, N; Krinichnaya, E; Krestinin, A; Loutfy, R; Morawsky, A; Muradyan, V; Obraztsova, E; Sloan, J; Terekhov, S; Zakharov, D (CARBON, 2001)