Answer:
The answer is other people have created.
Explanation:
Basically what we need to eliminate from this passage is a phrase that does not give us any specific and precise information.
contemporary historian - gives us information about his profession and specifies the part of the history he`s the most competent for.
historical expertise - gives us information about the kind of work he has published
other people have created - this phrase does not give us any information about who these people are, what is their profession or what is their expert level; it is mostly imprecise and unspecific
monotonous historical essays - again we have the information about the type of the paper published and its theme