Your manuscript should have a section titled 'References’ where you list your cited sources. All references should be cited, and vice versa. Try to avoid citing sources that haven’t been published yet or aren’t peer reviewed, and avoid excessively citing your own work.

You should order your references either:

  1. Numerically in the order they are mentioned in the text

  2. Alphabetically according to the first author

Most medical journals use a numbered system, but you should check what your journal wants.