First term	Second term
petroleum	york mercantile	0.2518
petroleum	new york mercantile	0.2105
petroleum	international monetary	0.1986
petroleum	singapore international moneta	0.1982
petroleum	gasoline	0.1753
petroleum	international financial	0.1513
petroleum	oil	0.1509
petroleum	nymex	0.1471
petroleum	gas	0.1429
petroleum	york cotton	0.1399
petroleum	singapore	0.1370
petroleum	mercantile	0.1349
petroleum	grain	0.1336
petroleum	hong kong futures	0.1321
petroleum	natural gas	0.1319
petroleum	securities and derivatives	0.1304
petroleum	crude	0.1283
petroleum	kansas city board	0.1270
petroleum	sugar	0.1185
petroleum	oil and gas	0.1154
petroleum	monetary	0.1153
petroleum	crude oil	0.1133
petroleum	africa	0.1117