Which works of Nietzsche are pure Nietzsche?

So, as far as I know, the book "Will to Power" is contaminated by his sister's own thoughts since Nietzsche never finished it personally. Because of this, no one is exactly sure which thought in this book comes from Nietzsche himself and which thought comes from his sister, right?

Is there any other book which is in doubt as to its influences? Like any other late books of his before he went mad? I'm thinking of The Antichrist for example