Finding journals for any specific topic can be challenging, because most journals cover a range of areas and topics, even when confined to a seemingly specific subfield. A good solution, if you don't know which journals you want, is to Google "journals" and your topic. Another way, if the topic is biological and or medical, is to use PubMed.org, which is run by the National Institutes of Health, and which anyone using federal NIH money is required to contribute to when they publish. A lot of universities and libraries can get free access to the full articles online, or at least have them on their shelves. The abstracts are all free. To read more in depth, take the reference to a library.