1. https://medlineplus.gov/overthecountermedicines.html
2. https://en.m.wikipedia.org/wiki/Over-the-counter_drug
3. https://www.aetnabetterhealth.com/illinois/assets/pdf/pharmacy/OTC-IL.pdf
4. https://www.slideshare.net/zainebRazzaq/abuse-and-misuse-of-medication
5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5774309/