Excerpt from Virtual Information in Data-Base Systems
Data relationships in recent information structuring models, however, essentially group and categorize data in some static fashion in the data base. But relationships can also be defined in a procedural fashion. An example of such an item is age. 'for example, to maintain a completely accurate value of someone's age, it would have to be updated continuously. Therefore, rather than assigning a particular stored Value to the data item age, it might be preferable to define it procedurally as current date minus data of birth. This leads directly to the idea that a model of information should allow not only static, grouping relationships.
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.