Hello. You did not present the document to which this question refers, which makes it impossible for it to be answered. In the meantime I will try to help you in the best possible way.
For a document to be a reliable source, it must have been written by an expert on the subject, it must have been written through long research that used sources written by experts, or it must be the report of someone who experienced the information being described in the document. Therefore, in relation to a document that presents the quality of public housing in Newark, we can consider it a reliable document, if it was written by a specialist who can prove whether these houses were of good or bad quality. In addition, if this document presents the account of people who lived in these homes and can testify about them, that document is also reliable.