DP - MPI Library TY - CHAP PY - 2008 AU - Schmookler, Jacob T1 - The level of inventive activity T2 - Innovation and growth SP - Vol. 1, S. 73 - 86 CY - London [u.a.] T3 - The economics of innovation ; 1 A2 - ed. by Cristiano Antonelli ET - 1. publ. PY - 2008 ER -