Books can be attributed to "Unknown" when the author or editor (as applicable) is not known and cannot be discovered. If at all possible, list at least one actual author or editor for a book instead of using "Unknown".
Books whose authorship is purposefully withheld should be attributed instead to Anonymous.
Hank Willis Thomas is one of my favorite artists. I'm lucky enough to have a few of his prints. This book captures the breadth of his work and reminds me why I love his work so much. His work is unflinching and biting but nods to a resilience and a hope that might save us yet.