TY  - BOOK
AU  - Ehlers, J.
TI  - LECTURE NOTES IN PHYSICS
SN  - 3 540 05698 X
U1  - 530.08 
PY  - 1971///
CY  - 
PB  - Springer-Verlag
UR  - http://link.springer.com/bookseries/5304
ER  -