I've been looking for freelancers or agencies to proofread a few articles and a booklet. I interviewed and talked to a lot of guys and discovered that not everyone is capable of doing such work. Then, fortunately, I discovered these guys and had a detailed discussion with them. Though I wasn't sure whether to put these guys to the test or not, I decided to go ahead with it. The contract worked out beautifully, and their editor did an excellent job. He discovered some very minor errors and corrected them with my approval. I wasn't expecting such high-quality work. Outstanding work.