Optimal multi-product supplier selection under stochastic demand with service level and budget constraints using learning vector quantization neural networkHajar HormozzadehGhalati, Alireza Abbasi and Abolghasem Sadeghi-NiarakiRAIRO-Oper. Res., 53 5 (2019) 1709-1720DOI: https://doi.org/10.1051/ro/2018096