[21: Abrufbar auf der Website des US-Außenministeriums: https://travel.state.gov/content/dam/visas/Statistics/Non-Immigrant-Statistics/RefusalRates/FY18.pdf.]
[21: Available at State Department website: https://travel.state.gov/content/dam/visas/Statistics/Non-Immigrant-Statistics/RefusalRates/FY18.pdf]