[peaceridge]

I promise I've both googled this and read the manual, but can't figure out how to do it. I have a lot of non-fiction books, some of which have been converted by Calibre to various formats. I do not convert pdf books that have a lot of pictures or use color for any particular reason. I'd like to find all of these so I can put them on my color ereader, but I don't want any that I've already converted to a different format.

I know I start out search with formats:"=PDF" , but how do I add also doesn't have any other format?

Thanks,