HAN, Y. W. ET AL.: 'Effect of single pyrrole replacement with beta-alanine on DNA binding affinity and sequence specificity of hairpin pyrrole/imidazole polyamides targeting 5'-GCGC-3', BIOORG MED CHEM, vol. 21, 2013, pages 5436 - 41, XP028690122, ISSN: 0968-0896, DOI: 10.1016/j.bmc.2013.06.005