Specify the name of the person(s) involved, why the source is relevant, and give as precise a date as possible. Get the approval to cite the person(s) involved and make sure you quote correctly.
Ex.: My teacher’s advice was: “don’t be afraid of making mistakes, that’s how we learn”. (D, Smith, personal communication, december 2016).
These sources are not included in the reference list.
Can be added as Personal communication in order to save the information.
Add as E-mail or Letter, and modify to suit requirements.