If you use trimAl, please cite:
trimAl: a tool for automated alignment trimming in large-scale phylogenetic analyses.
Salvador Capella-Gutierrez; Jose M. Silla-Martinez; Toni Gabaldon. Bioinformatics 2009 25: 1972-1973.
Here you can find the benchmark data used in the original paper as well as the description about how the data is organized.
Here you can find a short manual for trimAl 1.2: