Help with sources about 19th century Cambodia?

Dec 2014
I need some recommendations for books or articles (in English) about Cambodian history during the course of the 19th century, both before and after it became a French protectorate. I've been trying to find books myself but so much of the history seems to be published in Khmer or French, and I can't read either so I'm a bit stuck. Could anyone give me some suggestions for sources to brush up on this period of Khmer history?