TY  - RPRT
TI  - An Oscillation Theorem for Continuous Spectra.
AU  - P Hartman
AU  - A Wintner
PY  - 1947
DO  - 10.1073/pnas.33.12.376
UR  - https://pubmed.ncbi.nlm.nih.gov/16588770/
ID  - 16588770
ER  -