What format should sources be cited in a thesis Literature Review?
I think you want the link, with as much information as the link text can provide. So

Dumbledore [D1] contains spells X, Y and Z.

rather than

[3] contains spells X, Y and Z.

If you can find a document like yours (same level, same discipline) you can copy its style.
In any case, make a choice. If you use LaTeX properly you can change that globally with a macro change without having to edit the text.