Students who apply for admission to the Graduate School «Particle Detectors for Future Experiments» at the University of Mainz are asked to provide two references of senior scientists, who can provide an insightful assessment about the candidate’s abilities to thrive in the program. Referees are asked to submit a completed referee form (here) and email it from their institutional email account to particle-detectors@uni-mainz.de. The selection system is highly competitive and we kindly ask the referees to give their frank opinion about the academic and personal qualities of the candidate.