TY  - RPRT
TI  - Geometrically derived difference formulae for the numerical integration of trajectory problems
AU  - Mcleod, R. J. Y.
AU  - Sanz-Serna, J. M.
PY  - 1981
UR  - https://ntrs.nasa.gov/citations/19820020180
ID  - 19820020180
ER  -