This makes you wish the author would have written several advanced sequels to this amazing book.
You are right that "I wish he had written ..." is preferred.
However, in informal speech, "I wish he'd have written ..." and its variants, "I wish he had have written ..." and "I wish he would have written ...", though frequently considered incorrect, happen quite often in educated people's speech (according to entry 262.2 in PEU, see below).
I found this explanation in Practical English Usage by Michael Swan,
4 wish + that-clause: tenses
In a that-clause after wish, we generally use the same tenses as we would use, [...]. Past tenses are used with a present or future meaning.
Past perfect tenses are used for wishes about the past.
I wish you hadn't said that. (= It would be nice if you hadn't said that.)
Now she wishes she had gone to university.
In informal speech, sentences like I wish you'd have seen it sometimes occur. For similar structures with if, see 262.
Here are the relevant sections under entry 262 (for the usage of I wish you'd have ...).
262 if (7): other structures found in spoken English
2 'd have ... 'd have
In informal spoken English, if-clauses referring to the past are sometimes constructed with 'd have. This is frequently considered incorrect, but happens quite often in educated people's speech. It is not normally written.
If I'd have known, I'd have told you.
It would have been funny if she'd have recognised him.
3 had've and would've
Instead of the contracted 'd in these structures, full forms are sometimes used for emphasis or in negatives. Both had and would occur. The following are genuine examples taken from conversation.
I didn't know. But if I had've known ...
We would never have met if he hadn't have crashed into my car.
If I would've had a gun, somebody might have got hurt.
If you wouldn't have phoned her we'd never have found out what was happening.