We consider second order parabolic and elliptic systems with leading coefficients having the property of vanishing mean oscillation (VMO) in the spatial variables. An $L_q − L_p$ theory is established for systems both in divergence and non-divergence form.
"Parabolic and Elliptic Systems with VMO Coefficients." Methods Appl. Anal. 16 (3) 365 - 388, September 2009.