TY  - RPRT
TI  - The factor-ordering problem must be regulated.
AU  - NC Tsamis
AU  - RP Woodard
PY  - 1987
DO  - 10.1103/physrevd.36.3641
UR  - https://pubmed.ncbi.nlm.nih.gov/9958148/
ID  - 9958148
ER  -