Is the sentence grammatically correct?

You don't need both e.g. And brackets. One or the other.

The search is carried out using different sources of information (e.g. Library catalogues, subject databases or full texts). This would make more sense.

It's OK but can I suggest a tweak or two. We usually talk of a search being carried out ON a data source rather than 'at' a data source. When you said 'e.g.' were the following expressions really just examples from a larger range of sources or did you mean 'i.e.

'? What you wrote may be 100% correct. I have no way of knowing and mention it only as a possibility.

It is the "at" that is incorrect. "Using" might be better.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.