Slight polling glitch...

This weekend I set up a poll that I thought was set up so people could mark multiple answers. I've just discovered that feature didn't kick in. Since my intent was to see which writers of nonfiction history are familiar to my readers, I've replaced the malfunctioning poll with four individual polls. There are some more historians I intend asking about later, but I thought I'd start with these four.

My apologies to anyone who tried to mark multiple answers and couldn't.