TY  - RPRT
TI  - Photographic subtraction. II. Technical aspects and method.
AU  - C Hårdstedt
AU  - B Rundelius
AU  - U Welander
PY  - 1976
DO  - 10.1177/028418517601700110
UR  - https://pubmed.ncbi.nlm.nih.gov/773109/
ID  - 773109
ER  -