TY  - RPRT
TI  - Ulcerative colitis: "puzzles within puzzles".
AU  - J B Kirsner
PY  - 1970
DO  - 10.1056/nejm197003122821114
UR  - https://pubmed.ncbi.nlm.nih.gov/5413870/
ID  - 5413870
ER  -