"Public Health Notice – Outbreak of E. coli infections linked to romaine lettuce", Public Health Agency of Canada, February 9, 2018
Public Health Agency of Canada, "Public Health Notice - Outbreak of E. coli infections linked to romaine lettuce", November 20, 2018 [2]
cdc.gov
"Multistate Outbreak of Shiga toxin-producing Escherichia coli O157:H7 Infections Linked to Leafy Greens (Final Update)", Centers for Disease Control and Prevention, posted January 25, 2018