"Customs Ruling HQ 544887". U.S. Customs and Border Protection. October 2, 1992. Archived from the original on March 21, 2016. Retrieved October 12, 2014.
"Customs Ruling HQ 544887". U.S. Customs and Border Protection. October 2, 1992. Archived from the original on March 21, 2016. Retrieved October 12, 2014.