For more information on where to place in-text citations see the AMA Manual of Style sections 3.6 References. Citation. and 8.0 Punctuation.
Sources are cited in text using superscript numerals. These are placed outside periods and commas but inside colons and semicolons
For example:
Vondenberg reports that this intervention was a success1—contradicting the conclusions of an earlier study.2 According to Winroth et al,3 however...
Click here to learn how to format superscript in Microsoft Word.