Well, providing reference at the end of every question is necessary. You have to mention the reference to your End Term Assessment ETA question at the end.
If you are searching over the Internet and find an appropriate Answer then just copy the URL of that web page and write there. But, if you find the helping material from a book then do not forget to mention the Book Name and Page Number from where you got the material.
For example, if you are attempting an essay on Allama Muhammad Iqbal (R.A) and you find helpful material over Wikipedia then mention at the end of Question in this way,
Reference: [Wikipedia, https://en.wikipedia.org/wiki/Muhammad_Iqbal]
[Book: A visit to Iqbal’s Life by William Morris. Page Number: 238]
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