Reference is giving details,describing how you found it,were you found it, what gave you the idea from,and if you looked it up on the computer put what website you looked it up on,and if you found it in a book tell what was the title of the book and the chapter. I hope my definition helped you on your describing and if you are wondering I an not a teacher I am a student I'm 11years old
The word reference means the act of referring, or the state of being referred. In your case, since you are working on a science project it relates to the written work that you have consulted for your science project. The basic rule for report writing is that, one must acknowledge all the authors and their work, which has helped us in writing a report. You must have given only 3 references, and you teacher is asking for more references probably because he thinks there must be other references as well. So I suggest either include all books, journals, websites etc that you have taken help from, in your references or if there are only 3 then explain it to your teacher.
