| #291 | Oil and gas investor this week. -- Houston : Hart Energy Publishing, 1992-. -- ISSN 1940-5189 print. -- ISSN 1940-5197 online |
| #292 | Oil and gas investor's A & D watch. -- Potomac : Hart Energy Publications, 2001-. -- ISSN 1940-8471 print. -- ISSN 1940-848X online |
| #293 | Oil & gas interests newsletter. -- Houston : Tamarack Consulting, 1986-. -- ISSN 1073-0265 |
| #294 | Oil & gas investor. -- Denver : Investor Pub. Co., 1981-. -- ISSN 0744-5881 |
| #295 | Oil & gas journal. -- Tulsa : PennWell, 1910-. -- ISSN 0030-1388 print. -- ISSN 1944-9151 online |
| #296 | Oil, gas & petrochem equipment. -- Tulsa : Petroleum Pub. Co., 1969-. -- ISSN 0030-1353 |
| #297 | Oil Shale. -- Tallinn : Estonian Academy Publishers, 1984-. -- ISSN 0208-189X print. -- ISSN 1736-7492 online |
| #298 | Oilweek. -- Calgary : Maclean-Hunter, 1958-1995. -- ISSN 0030-1515 |
| #299 | Ökoenergie : Magazin zur Főrderung erneuerbarer Energie und der Energieeffizienz. -- Wien : Ökosoziales Forum Österreich |
| #300 | Oman oil & gas report. -- London : Business Monitor International, 2005-. -- ISSN 1748-4138 |