olemus
neli maailma suurimat auditi- ja konsultatsioonikompaniid:
PwC (PricewaterhouseCoopers)
DTTL (Deloitte Touche Tohmatsu Limited)
E & Y (Ernst & Young)
KPMG (Klynveld Peat Marwick Goerdeler)
= the four largest professional services networks in the world, consisting of the global accounting networks Deloitte, Ernst & Young, KPMG and PwC

ülevaateid
https://en.wikipedia.org/wiki/Big_Four_accounting_firms
http://www.big4accountingfirms.org/