TY  - DATA
AU  - Laura Maraschi, Tommaso Maccacaro, Marie-Helene Ulrich
TI  - BL Lac Objects
SN  - 9783540462033
PY  - 1989///
PB  - Springer Berlin Heidelberg
KW  - Physics and Astronomy
UR  - https://doi.org/10.1007/BFb0031137
ER  -