APA

National Cancer Institute (U.S.), . (19). Carcinoembryonic antigen in benign and malignant diseases of the digestive tract. [Washington, D.C: .

Chicago

National Cancer Institute (U.S.), . 19. Carcinoembryonic antigen in benign and malignant diseases of the digestive tract. [Washington, D.C: .

Harvard

National Cancer Institute (U.S.), . (19). Carcinoembryonic antigen in benign and malignant diseases of the digestive tract. [Washington, D.C: .

MLA

National Cancer Institute (U.S.), . Carcinoembryonic antigen in benign and malignant diseases of the digestive tract. [Washington, D.C: . 19.