Regulations
RECOMMENDATIONS FOR ENTERING ENCLOSED SPACES ABOARD SHIPS RESOLUTION A.864(20)
http://www.imo.org/blast/blastDataHelper.asp?data_id=24008&filename=864(20).pdf
REVISED RECOMMENDATIONS FOR ENTERING ENCLOSED SPACES ABOARD SHIPS RESOLUTION A.1050(27)
http://www.imo.org/en/KnowledgeCentre/IndexofIMOResolutions/Documents/A%20-%20Assembly/1050(27).pdf
Emergency training and drills - 3.6 Enclosed space entry and rescue drills
http://www.imo.org/en/Publications/Documents/Supplements%20and%20CDs/English/QF110E_122014.pdf
Entry into Dangerous Spaces MGN 423 (M)
The Merchant Shipping (Entry into Dangerous Spaces) Regulations 1988
http://www.legislation.gov.uk/uksi/1988/1638/contents/made
Code of Safe Working Practices for Merchant Seafarers 2019 – Chapter 11.10 and Chapter 15 Entering Dangerous (Enclosed) Spaces
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/886670/Code_of_safe_working_practices_for_merchant_seafarers_2019.pdf