1. Scientists, U.S. counter claims of pandemic patient zero at lab;J Cohen;Science,2023
2. Covid origin: Why the Wuhan lab-leak theory is so disputed;Bbc;BBC News,2023
3. Use of a risk assessment tool to determine the origin of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2);X Chen;Risk Anal,2024
4. Intelligence on Sick Staff at Wuhan Lab Fuels Debate on Covid-19 Origin;M R Gordon;The Wall Street Journal,2021