Sometimes during your research you may find that there is little information on your original research topic and you'll have to expand the topic a little. It can be frustrating and tedious but with creativity and hard work, it is possible. In some cases, one reason why you can't find enough information on your original topic is because not enough scholarship has been produced on it.
Add a new area of research to what scholars have already done. If you've read articles that have focused on sex tourism in Latin America and its impact on poor women, you can build on that topic by writing about how certain political issues and a lack of economic resources lead to this choice of work. You can also include the impact this has on the children of sex workers in the tourism industry.
Write about the larger issues concerning your research topic. For example, if you wanted to write about how hip-hop music has allowed young African-American men to consider entrepreneurship as a possible option for economic success, you can mention larger issues such as the problems of inner-city crime, poor educational systems in certain cities, the breakdown of the traditional family and issues of race and class as factors motivating young African-American men to consider a career in hip-hop.
Talk with your professor. Your professor has many years of conducting research and will be able to help you expand your topic. If you're conducting research on Afro-Mexicans but not much has been written recently about them, your professor may want you to expand your research to the social and economic issues that different indigenous groups in Mexico face daily and how they mobilize for human rights.