Many of the article citations you find by searching the article databases will link directly to the fulltext of the articles. Sometimes, however, you may find a citation somewhere such as another article's reference list, or someone may recommend a particular journal title. In that case, you will have to check to see if the Library either has access to the fulltext of the journal online or a print or microform copy in the Library.
To see if a particular journal is in the Libraries' collection, or to browse journal titles by discipline, use Journal/E-Book List. If you have a citation and want to see if the book or article is available in the USA Libraries, use Look Up a Citation.
This is a sampling of journals, available fulltext through the Library, that may be relevant for your research. It is not an exhaustive list and there are many others which may be found by searching the Article Databases.