9ISO 13628-2--2006 Petroleum and natural gas industries Design and operation of subsea production systems Part 2: Unbonded flexible pipe systems for subsea and marine applications[S]. 2006 : 54-56.
10ISO 13628-4--1999 Petroleum and natural gas industries design and operation of subsea produetion systems Part 2: subsea wellhead and tree equipment[S]. 1999.
