TY  - RPRT
TI  - A THEOREM ON STABILITY OF COMPLEX STRUCTURES.
AU  - A Frölicher
AU  - A Nijenhuis
PY  - 1957
DO  - 10.1073/pnas.43.2.239
UR  - https://pubmed.ncbi.nlm.nih.gov/16590006/
ID  - 16590006
ER  -