Some asymmetrical weighing and $2^n$ fractional factorial designs are proved to be optimal over all possible designs with respect to a very general class of criteria. This strengthens and unifies many previously published results in this area. An easy method to prove E-optimality is also presented.
"Optimality of Some Weighing and $2^n$ Fractional Factorial Designs." Ann. Statist. 8 (2) 436 - 446, March, 1980. https://doi.org/10.1214/aos/1176344963