Chen, J., Ye, X., Oh, S.J., Kikkawa, J.M., Kagan, C.R., Murray, C.B. Bistable magnetoresistance switching in exchange-coupled CoFe2O4-Fe3O4 binary nanocrystal superlattices by self-assembly and thermal annealing. ACS Nano 2013, 7, 1478-1486.