Differences in clinical and immunologic reactivity of patients allergic to grass pollens and to multiple-pollen species. II. Efficacy of a double-blind, placebo-controlled, specific immunotherapy with standardized extracts. - Bousquet,J.; Becker,W.M.; Hejjaoui,A.; Chanal,I.; Lebel,B.; Dhivert,H.; Michel,F.B. (J Allergy Clin Immunol, 1991)