This application for teaching assistantship is not an application for admission. All TA applicants must also submit an application for admission to the desired graduate program.
The online application for admission will ask for at least three references to write letters or recommendation. Let your references know that you are applying for a TA so that they can address your ability to communicate and teach a class.
Applicants are encouraged to complete both TA and admission applications by Feb. 15, although late applications will be accepted.