Talavera, G., and Castresana, J. (2007). Improvement of phylogenies
after removing divergent and ambiguously aligned blocks from protein
sequence alignments. Systematic Biology 56, 564-577.

Castresana, J. (2000). Selection of conserved blocks from multiple
alignments for their use in phylogenetic analysis. Molecular Biology
and Evolution 17, 540-552. 
