TY  - RPRT
TI  - The systems approach.
AU  - A J Wildman
PY  - 1973
DO  - 10.1043/0003-3219(1973)043<0088:tsa>2.0.co;2
UR  - https://pubmed.ncbi.nlm.nih.gov/4509529/
ID  - 4509529
ER  -