4[1]Ingolf Dittmann. How reliable should auditors be?: Optimal monitoring in principal- agent relationships[J]. European Journal Political Economy, 1999,5:523 - 549.
5[2]Tirole,J. Collusion and the theory of the organizations[C]. Advances in Economic Theory, 6th World Congress of the Econometric Society, 1992,2:152 - 206.
6[3]Tirole,J. Hierarchies and bureaucracies: on the role of collusion in organization[J]. Journal of Law, Economics and Organizaition, 1986,2:181- 214.
7[4]Fred Kofman, Jacques Lawarree. On the optimality of allowing collusion [J]. Journal of Public Economics, 1996,61:384 - 407.
8[5]Fred Kofman, Jacques Lawarree. A prisoner's dilemma model collusion deterrence[J]. Journal of Public Economics, 1996,59:117 - 136.
9[6]Laffont, Tirole. Using cost observation to regulate finns [J]. Journal of Political Economy, 94,614 - 641.
10[7]Fred Kofman, Jacques Lawarree. Collusion in hierarchical agency [ J ].Econometrica, 1993,61:629 - 656.
