https://abc7news.com/stanford-coronavirus-study-number-people-infected-by-santa-clara-county-total-covid-19/6110894/

Coronavirus spread: Number of people infected by COVID-19 may be 50-80 times higher than official count, Stanford study suggests

Additional sauce

https://www.medrxiv.org/content/10.1101/2020.04.14.20062463v1