ISA 540

I am studying “ISA 540 – auditing accounting estimates and fair value” for my thesis. I face difficulties in finding the history of this ISA, eg, when is the first issuance, how many times was it revised and redraft? Key changes of each time? I know after the clarify project in 2003, ISA 540 and ISA 545 were combined into ISA 540, so the scope of this ISA is widen and include fair value. Can someone help me on this? Thanks.