1. Cytologic intragastric brushing under direct vision: a new gastric brush;Christopher;Gastrointestinal Endoscopy,1969
2. Gastroscopic brush-cytology: a supplement to gastric biopsy in earlier diagnosis of cancer;Wiendl;Endoicopy,1974
3. Handbook and Atlas of Gastrointestinal Exfofiative Cytology;Prolla,1972
4. Directed cytology of the esophagus and stomach: a comparison of 3 rapid collection methods;Graham;Gastrointestinal Endosropy,1978
5. Direct-vision endustopic cytology and biopsy in the diagnosis of esophageal and gastric tumors: current experience;Prolla;Acta Cytol,1977