| iso.ch | ISO. International Organization for Standardization |
| api.org | American Petroleum Institute |
| ansi.org | American National Standards Institute |
| techstreet.com | Techstreet |
| sciencedirect.com | ScienceDirect |
| ihserc.com | Ihs Standards, Regulations, Information Solutions - Global Engineering Document |
| steel.org | American Iron and Steel Institute |
| nssn.org | NSSN: A National Resource for Global Standards |
| nist.gov | National Institute of Standards and Technology (NIST) |
| nfpa.org | National Fire Protection Association |
| micronexx.com | search.micronexx.com/ |
18890