TY  - RPRT
TI  - DECLINING TUBERCULIN SENSITIVITY WITH ADVANCING AGE.
AU  - R N JOHNSTON
AU  - R T RITCHIE
AU  - I H MURRAY
PY  - 1963
DO  - 10.1136/bmj.2.5359.720
UR  - https://pubmed.ncbi.nlm.nih.gov/14043732/
ID  - 14043732
ER  -