Choice of Reference

Hello everyone, I am a undergra student planning to apply for a postgraduate school. I think three of the lecturers are willing to write reference for me, who are my temporary personal tutor, my dissertation tutor and a teaching fellow who will be working in Oxford/Cambridge in November. Most unis normally require two references. My temporary personal tutor was my lecturer one year ago, and he just became my personal tutor since the original personal tutor went away to some other country. My dissertation is a senior lecturer. The teaching fellow is very nice and he will not be working in the school for which I will apply till October or November. They all taught economics-related subjects before, and none of them taught me exactly the same course as what I am going to apply in Postgra. Who should I ask reference for?Would be much appreciated if you could provide any hints.