Write novel and cite functions.
> novel ("Rowling", "Harry Potter", 1998)
"Harry Potter (Rowling, 1998)"
> cite [("author1", "book1", year1), ("author2", "book2", year2), ("author3", "book3", year3)]
"book1 (author1, year1)
book2 (author2, year2)
book3 (author3, year3)"