Can you publish and sell a book of essays you have written if they contain cited information from other sources or do you have to get permission from every source used even if it's only a statistic?

Can you publish and sell a book of essays you have written if they contain cited information from other sources or do you have to get permission from every source used even if it's only a statistic?
Considering the number of books comprised of essays on the market I don't doubt you could publish a collection of them, although you will have to credit every single source you've ever used in that case. You will also have to find a publisher willing to put that book in print, and then possibly endure extensive lambasting from critics, depending on the field in which you are writing said essays.

If the source is available for public perusal on information databases you can get away with using the source without asking for permission as long as you cite the source from which it came, though this has probably already been beaten into your head repeatedly by whoever taught you to write academic papers or your essayist skills in general. You only need to get permission if the source states that request of such is required. It is probably polite to request permission anyway, regardless of whether or not it is required.