1.. Krauss-Etschmann, S., et.al. (2009). Journal of Allergy and Clinical Immunology, 123 (5), 1176-1178. 2. FDA (US) (2018). Asthma_ The Hygiene Hypothesis. Retrieved from: https://www.fda.gov/vaccines-blood-biologics/consumers-biologics/asthma-hygiene-hypothesis 3. FHS (HK). Retrieved from https://www.fhs.gov.hk/tc_chi/health_info/child/20000.html#ch1_1 4. FHS (HK) (updated on 2021). Food Allergy. Retrieved from : https://www.fhs.gov.hk/tc_chi/health_professional/OMP_eNewsletter/enews_20151030.html
5. Bode, L. (2012). Glycobiology, 22(9), 1147-1162. 6. von Berg, A., et al. (2016). Allergy, 71(2), 210-219. 7. von Berg, A., Koletzko, S., Grübl, A., et al. (2003). Journal of Allergy And Clinical Immunology, 111(3), 533-540. 8. Gappa, M. et al., (2020). Allergy, 00,1-5. 9. Billeaud, C., et al. (1990). European Journal of Clinical Nutrition, 44, 577-583