The term microemulsion was first used by T. P. Hoar and J. H. Shulman, professors of chemistry at Cambridge University, in 1943. Alternative names for these systems are often used, such as  transparent emulsion, swollen micelle, micellar solution, and solubilized oil.  More confusingly still, the term microemulsion can refer to the single isotropic phase that is a mixture of oil, water and surfactant, or to one that is in equilibrium with coexisting predominantly oil and/or aqueous phases, or even to other non-isotropic phases. As in the binary systems (water/surfactant or oil/surfactant), self-assembled structures of different types can be formed, ranging, for example, from (inverted) spherical and cylindrical micelles to lamellar phases and bicontinuous microemulsions, which may coexist with predominantly oil or aqueous phases.