| | isobutane on Encyclopedia.com (Site not responding. Last check: 2007-09-10) |
 | | Enterprise Products Partners L.P. Announces Major Isobutane Contract Renewal. |
| | Solubility of butane and isobutane in molten polypropylene and polystyrene. |
| | Appendix C: impact of resubmissions on major series, 2003. |
| www.encyclopedia.com /html/X/X-isobutan.asp (228 words) |
