Robuta

https://www.bls.gov/cps/certifications-and-licenses.htm Data on certifications and licenses (CPS) : U.S. Bureau of Labor Statistics Data on certifications and licenses (CPS) certifications and licenses https://www.bls.gov/opub/mlr/2016/article/adding-questions-on-certifications-and-licenses-to-the-current-population-survey.htm Adding questions on certifications and licenses to the Current Population Survey : Monthly Labor... the current population survey certifications and licenses