Average Frobenius distributions for elliptic curves over abelian extensions Neil Calkin, Bryan Faulkner, Kevin James, Matt King, David Penniston (2011) Acta Arithmetica
Average Frobenius distributions for elliptic curves with nontrivial rational torsion Jonathan Battista, Jonathan Bayless, Dmitriy Ivanov, Kevin James (2005) Acta Arithmetica