Feldman RM, Tanna AP, Gross RL, Chuang AZ, Baker L, Reynolds A, Prager TC. Comparison of the ocular hypotensive efficacy of adjunctive brimonidine 0.15% or brinzolamide 1% in combination with travoprost 0.004%. Ophthalmology. 2007 Jul; 114(7):1248-54.