Citation generators allow you to enter your source's bibliographic information (such as title and author for a journal article, web page, or book) in order to produce a citation in your selected format.
Refworks is a citation manager that imports citations from many library databases and Google Scholar, enables you to attach PDFs to citations, add notes, and generates bibliographies in many formats, including APA or MLA. Set up a free account using your Hostos email address.
Free citation builders
These are owned by universities, are entirely free and have no ads. You put in your information and they will put everything in the correct format. They will not, however, try to look up any information that you are missing.
Commercial citation generators
BibME Citation Machine EasyBib - these are now all owned by the Chegg Company, and are very similar. They can sometimes fill in information that you are missing, but you may still need to fill in several blanks about author, volume, publisher, date of publication, etc., to create a correct citation. These are commercial websites and will display many ads.
Some library databases have built-in citation generators that allow you to click on a "Cite" button to get a citation for that article or book. (Also see the citation generator embedded in OneSearch, below.)
Note: Always double-check the citations generated through these tools, which can make errors.
Citation management software
People who are collecting and organizing dozens or literally hundreds of citations--such as students working on a senior thesis, graduate students working on dissertations, and professors writing books or journal articles for peer-review--often use citation management programs.
If you only need to format 5-10 citations for your project, these programs may not be worth the time it takes to learn to use them - but if you are curious, by all means check them out and see what they're about!
When you find items in OneSearch, you can click on the citation tool above the short description:
Clicking on the tool will open a box in which you can choose your citation style and then copy the citation: