I'm reading Impagliazzo and Wigderson's famous $\mathsf P=\mathsf{BPP}$ paper in 1997.  Since I'm new to this field and the paper is a concise conference version, I have difficulty following their proofs.  In particular, some of their new theorems lack proofs.  To my best knowledge there hasn't been a journal version published.I'm looking for resources from which I can learn their result, preferably those with formal proofs.  I'd be very grateful if you could tell me about such resources.
Impagliazzo and Wigderson's famous P=BPP paper
cc.complexity theory;reference request;circuit complexity;derandomization;pseudorandom generators
Check Chapter 7 of Salil Vadhan's monograph. Corollary 7.64 is Impagliazzo and Wigderson's result.