. "FIXED POINT THEOREMS ON HILBERT SPACES VIA WEAK EKELAND VARIATIONAL PRINCIPLE Vol. 4(2) July. 2016, No. 24, pp. 266-271 M. BRIKI AND T. MOUSSAOUI", Electronic Journal of Mathematical Analysis and Applications, 4, 2, 2016, -. doi: 10.21608/ejmaa.2016.310858