American Institute of Chemical Engineers. Center for Chemical Process Safety. (2014). Guidelines for enabling conditions and conditional modifiers in layers of protection analysis. John Wiley and Sons, Incorporation.

American Institute of Chemical Engineers. Center for Chemical Process Safety. Guidelines for Enabling Conditions and Conditional Modifiers in Layers of Protection Analysis. Hoboken, New Jersey: John Wiley and Sons, Incorporation, 2014.

American Institute of Chemical Engineers. Center for Chemical Process Safety. Guidelines for Enabling Conditions and Conditional Modifiers in Layers of Protection Analysis. John Wiley and Sons, Incorporation, 2014.