4Summers A E. Introduction to layers of protection analysis[J]. Journal of Hazardous Materials, 2003, 104(1/2/3) : 163-168.
5Vaidhyanathan R, Venkatasubramanian V. A semi- quantitative reasoning methodology for filtering andranking HAZOP results in HAZOP Expert [ J]. Reliability Engineering and System Safety, 1996, 53 (2) : 185-203.
6Stack R J. Evaluating non-independent protection layers[ J ]. Process Safety Progress, 2009, 28 ( 4 ): 317- 324.
7Baybutt P. Layers of protection analysis for human factors [ J]. Process Safety Progress, 2002, 21 (2) : 119-129.