TY  - BOOK
AU  - Hall, Bronwyn H
AU  - Helmers, Christian
AU  - Graevenitz, Georg Von
ED  - National Bureau of Economic Research
TI  - Technology entry in the presence of patent thickets
T2  - NBER Working Paper
PY  - 2015///
CY  - Cambridge
PB  - NBER
KW  - NBERWP 21455
KW  - E15288.pdf
UR  - http://elibrary.igidr.ac.in/e-library/working papers/NBER/2015/E15288.pdf
ER  -