David Said:

Job Application and Cover Letter Questions?

We Answered:

I understand what you mean by the reasons because currently I am applying jobs as well.:)
Don't tell them that parents made you quite to do school and such. People would think you don't stick to your principles but are subject to others' ideas easily.
Tell them the contract expired and you wanted to try something new if you did sign a contract. Or say that school work was overwhelming by that time and you think education is too important that you had to make the decision to leave although you really loved the job.
For the references, you can try to fill it with a teacher who knows you well(you gotta get the permission from the teacher).
Best luck of all. :)