1. New challenges: Voltage stability;Clark;IEEE Power Eng. Rev.,1990
2. Tamura, Y., Mori, H. and Iwanoto, S 'Relationship between voltage instability and multiple load flow solutions in electric power systems' IEEE Trans. Vol PAS-102 pp 1115–1125
3. Voltage collapse prediction using an improved sensitivity approach;Crisan;Electr. Power Syst. Res.,1984
4. Estimating the voltage stability of a power system;Kessel;IEEE Trans. PWRD,1986
5. Voltage stability indices of stressed power systems;Lof;IEEE Trans. PWRS,1993