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.
This edition ( (c)1979) was half written, half drawn in that the sentences were mostly written text but ended with a drawing.
For instance, the gingerbread boy's line about running away from the little old man was all written until you got to "little," then a simple picture of the little "old man" ended the sentence.
I can see how this might be exciting for a kid to read (and that's all that matters as it is a kid's book), but it took a little getting used to for me.
Still, I was able to read it through in under 5 minutes, so...