G. B. Ouellette, D. Rioux, M. Simard, H. Chamberland, M. Cherif, and R. P. Baayen, “Ultrastructure of the alveolar network and its relation to coating on vessel walls in elms infected by Ophiostoma novo-ulmi and in other plants affected with similar wilt diseases”, For. syst., vol. 13, no. 1, pp. 147-160, Apr. 2004.