TY  - RPRT
TI  - Time ordering of two-step processes in energetic ion-atom collisions: Basic formalism.
AU  - N Stolterfoht
PY  - 1993
DO  - 10.1103/physreva.48.2980
UR  - https://pubmed.ncbi.nlm.nih.gov/9909948/
ID  - 9909948
ER  -