Dark optical solitons of Biswas-Milovic equation with dual-power law nonlinearity M. Mirzazadeh, M. Eslami and Ahmed Hassan Arnous Eur. Phys. J. Plus, 130 1 (2015) 4 Published online: 12 January 2015 DOI: 10.1140/epjp/i2015-15004-x