Official UN3373 Regulation Resources

The absolute rules for shipping Dangerous goods by air.

http://www.iata.org/whatwedo/cargo/dgr/Documents/infectious-substance-classification-DGR56-en.pdf

http://www.iata.org/whatwedo/cargo/dgr/Documents/packing-instruction-650-DGR56-en.pdf

Government website

A guide to the international regulations on the transportation of dangerous goods by air, sea, road, rail or inland waterway

https://www.gov.uk/guidance/moving-dangerous-goods#regulations-for-transporting-dangerous-goods-by-air-sea-road-and-rail-transport

International Civil Aviation Organisation (ICAO)

Technical Instructions for the Safe Transport of Dangerous Goods by Air

http://www.icao.int/publications/Documents/
guidance_doc_infectious_substances.pdf

Department for Transport, HSE, Maritime and Coastguard Agency and Civil Aviation Authority

Transport of infectious substances UN2814, UN2900 and UN3373

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/917954/dangerous-goods-guidance-note-17-document.pdf

World Health Organisation

Transport of Infectious Substances

https://www.who.int/publications/i/item/789240089525

Royal Mail

IATA Guidance Document Infectious Substances

http://www.royalmail.com/sites/default/files/Guidance-Document-Infectious-Substances-171012.pdf