The phrase "to write these references" means to create or compose documents or letters that talk positively about someone's skills, experiences, or character, typically used when someone is applying for a job or a position. Full definition
A cover letter is drafted for multiple purposes like; job acceptance, salary negotiation, drafting resignation, thanking the employer, or for writing a reference letter for suggestion and many more. (bestcoverletters.com)
Ask for written references from current and former banks or lending institutions. (moneysense.ca)
It is not really necessary to follow a set format when writing a reference letter for an employee. (coverlettersandresume.com)