TY - RPRT TI - Small DNA deletions creating avirulence in Streptococcus pyogenes. AU - J G Spanier AU - S J Jones AU - P Cleary PY - 1984 DO - 10.1126/science.6089334 UR - https://pubmed.ncbi.nlm.nih.gov/6089334/ ID - 6089334 ER -