S. Choudhury, M. A. Bhuiyan, and S. M. Hoque, “Retracted: Effect of sintering temperature on apparent density and transport properties of NiFe2O4: synthesized from nanosize powder of NiO and Fe2O3”, Int. Nano Lett., vol. 2, no. 1 (December 2012), Jun. 2012, doi: 10.1186/2228-5326-2-6.