How do you know if you have enough sources?

[macbug]

3. If you have to ask that question you are in more trouble than you think.

One) you do not know your audience.
Two) you do not know the subject.
Three) you are not qualified to write on the subject.
Four) your opinion and or knowledge of the subject is so limited you do not have confidence in writing about it.
Five) you are jesting and seeing how many of us are foolish enough to take the question seriously.
Six) my opinion means nothing to you and I am the one who should check his sources.
Seven) do what I do, stick to fiction and make it up as you go and you can always be accused of plagiarism, but since you have no sources they can never convict you.