Is "each of them have contribute to are as followed:" correct in this sentence?

Question

Is the sentence in bold correct? This excerpt is from a manuscript I'm editing:

Then there were a number of new researches published before the second edition of this book went to print, which are not mentioned individually in order not to make the list too long. Some additions and revisions have been made in the second edition, but we have tried not to make major changes to the book. The writers and chapters each of them have contribute to are as followed:

I think sentence construction used here is wrong because of following reasons:

1. "contribute" should be changed to "contributed".
2. There are two verbs without relative clause.

Answer 1

There are multiple errors in the sentence. Below are two grammatically correct possibilities. The second sentence would be preferable in formal written English.

The writers and chapters each has contributed to are as follows.

The writers and chapters to which each has contributed are as follows.

To break it down a little, the subject of the sentence is writers and chapters. The verb are is present tense, and so as follows should also be present tense.

Each has contributed to and to which each has contributed are present-perfect phrases that modify chapters. In formal English, ending a phrase (and especially a sentence) with a preposition like upon or with is frowned upon. This is not a rule to be messed with. You can read more about it here: http://grammar.yourdictionary.com/parts-of-speech/prepositions/Ending-a-Sentence-with-a-Preposition.html