Completely regular growth of solutions to linear differential equations with exponential polynomial coefficients

Consider the linear differential equation $f^{(n)}+A_{n-1}f^{(n-1)}+\cdots+A_0f=0$, where the coefficients are exponential polynomials. We prove that every finite-order transcendental entire solution has completely regular growth and obtain asymptotic formulas for $\log|f|$ on almost every ray. This