Heladia Salgado Alberto Santos-Zavaleta Ulises Garza-Ramos Jacques van Helden Edgar Díaz-Peredo Julio Collado-Vides 59-60 1999 27 Nucleic Acids Research 1 db/journals/nar/nar27.html#SalgadoSGHDC99 http://dx.doi.org/10.1093/nar/27.1.59