Citation generators can be very useful in sparing researchers from the drudgery of manually creating citations, in the same way that dishwashers can spare you from the drudgery of hand-washing dishes. However, students should be advised to use them with caution: just as you often have to scrub dishes after they come out of the dishwasher, citation generators do not always give completely accurate results. You still need to know the basic principles of whatever citation method is being used and sometimes tweak the results.
I recommend the following free citation generators:
For help using Zotero, take a look at our step-by-step guide.