Global Logistics Associates (GLA):

http://www.globallogisticsassociates.com/

NSBS:

http://nsbs.bg/en/home

ISO sea containers dimensions:

http://en.wikipedia.org/wiki/Intermodal_container

CMR:

http://www.jus.uio.no/lm/un.cmr.road.carriage.contract.convention.1956.amended.protocol.1978/doc.html

List of UN numbers for dangerous cargo:

http://en.wikipedia.org/wiki/Lists_of_UN_numbers

ITMS – Taric Consultation Module (HS codes):

http://www.customs.bg:55080/tariccm/tariccm/main_EN?Year=&Month=&Day

Bulgarian Customs Agency:

http://www.customs.bg

European Customs Information Portal:

http://ec.europa.eu/ecip/help/glossary/index_en.htm