Fascicolo 98-99-100/2001 Emilio Spedicato, Foreword Ladislav Luksan, Emilio Spedicato, A globally convergent nonlinear ABS algorithm, theory and numerical experiments Li-Wei Zhang, Zun-Quan Xia, ABS algorithms for solving linearly constrained optimization problems via the active set strategy Li-Wei Zhang, Zun-Quan Xia, Yong-Jin Liu, Application of the ABS method to systems of linear matrix integer equations Li-Wei Zhang, Computing inertias of KKT matrix and reduced Hessian via the ABS algorithm Yong Wang, En-Min Feng, On the use of ABS algorithms in the modelling of oil deposits