It's funny ("funny") how much police work operates like how I wrote papers in high school.
Write it from one (possibly unapproved, but convenient) source, find citations for various passages in several books after it's done, mostly by using the index to find exactly what's needed to avoid needing to read more than a couple paragraphs of each book, until the "minimum sources" number is hit.
Write it from one (possibly unapproved, but convenient) source, find citations for various passages in several books after it's done, mostly by using the index to find exactly what's needed to avoid needing to read more than a couple paragraphs of each book, until the "minimum sources" number is hit.