Funds that invest in emerging markets debt follow a variety of approaches. Some managers focus exclusively on bonds that that are denominated in dollars -- not in the currencies of the countries issuing the debt. Other funds emphasize bonds denominated in foreign currencies. In the past, many investors preferred the dollar bonds because they would not necessarily collapse if the foreign currencies fell. These days many investors favor local currency issues, which can strengthen as emerging markets grow. To hold a broad collection of bonds, consider TCW Emerging Markets Income, which has returned 13.4% annually during the past five years, ranking as the top performer in the category. The fund yields 5.5%. TCW follows a wide-ranging approach, emphasizing dollar bonds some years and shifting to foreign currencies at other times. Lately the fund has been increasing its exposure to local currencies. IHIAX), which returned 10.1% annually during the past five years, outdoing 70% of peers. Federated can hold dollar or local currency bonds. These days the portfolio managers are emphasizing dollar securities. Portfolio manager Roberto Sanchez-Dahl concedes that many currencies appear sound. But he worries that local currencies can be volatile during periods when investors flee risky assets. Sanchez-Dahl is particularly keen on government bonds from Peru and Colombia, two countries that have been upgraded to ratings of BBB, the lowest investment-grade rating. The bonds yield 5%, while comparable U.S. securities yield about 3.5%. "You can get a nice yield premium from BBB issuers in the emerging markets," he says. A fund that holds a mix of government and corporate bonds is Goldman Sachs Emerging Markets Debt ( GSDAX), which returned 10.1% annually during the past five years. Portfolio manager Samuel Finkelstein has big stakes in investment-grade countries, such as Mexico and Turkey. But he is also willing to hold some below-investment grade issues. Favorite holdings include bonds from the Ivory Coast, which yield 7.3%. The country defaulted on its bonds several years ago when a civil war disrupted the economy. But lately peace has returned, and the bond prices have jumped 80% in the past year. "The country has come a long way and reinstated coupon payments," says Finkelstein. REBAX), which has returned 10.8% annually during the past five years. The fund yields 5.0%. Portfolio manager James Carlen likes local currency Mexican bonds, which yield 5.5%. "Mexico has an independent central bank that has a strong focus on controlling inflation," he says. At the time of publication the author held no positions in any of the stocks mentioned. Follow @StanLuxenberg This article is commentary by an independent contributor, separate from TheStreet's regular news coverage.