1. Ait Rami M, Moore JB, Zhou XY (2001) Indefinite stochastic linear quadratic control and generalized differential riccati equation. SIAM J Control Optim 40(4):1298–1311
2. Buratto A (2002) Budget allocation in the integrated ommunication mix. Rendiconti degli studi Economici e Quatitativi, pp 89–104
3. Buratto A, Favaretto D (2002) Optimal communication mix to maximize brand image. Ricerca Operativa 103/104:33–50
4. Buratto A, Viscolani B (2002) New product introduction: goodwill, time and advertising cost. Math Methods Oper Res (55):55–68
5. Chen S, Li X, Zhou XY (1998) Stochastic linear quadratic regulator with indefinite control weight costs. SIAM J Control Optim 36(5):1685–1702