US visa nightmares.
D004641:Emigration and Immigration / Q000331:legislation & jurisprudence* / Q000706:statistics & numerical data; D004651:Employment / Q000331:legislation & jurisprudence; D012108:Research Personnel / Q000331:legislation & jurisprudence*; D047851:September 11 Terrorist Attacks; D013334:Students / Q000331:legislation & jurisprudence; D013997:Time Factors; D014481:United States; D037041:United States Government Agencies / Q000331:legislation & jurisprudence*