No,4

The historical story makes readers know background or remember what they stdied before. The memoir that Elizer gives us his story in that case according to fact and these are interacted with each other in order to make a book, Night. Therefore, I think that memoir is good source because how we know about books is imageing, so it is a really effective source to understand the book. For example, we know about what happened to them at the time mostly, but books of memoir give us much more details, such as using what he said and how he felt.