Where can i find a good Doberman Breeder?

My husband and I are looking for a Doberman breeder so we can purchase a red female Doberman of good tempermant and who's parents and itself have been health checked.I live in maryland although i am willing to look in MD, VA, DC, PA and NC. I love dobermans I have owned them before. I know a lot of about them and I understand everything that goes into owning one..I am basically just looking for a reference from someone who purchased a great doberman in my area or could point me to someone who is has a very good reputation of breeding good Dobermans. Serious answers only. Thank you!