M currently doing my MBA in marketing and want to go for a Phd programme in marketing in US and would require financial assistance as well.My academic record has been good, will that help in getting assistance? Please suggest me the universities where i can apply and when is the right time to write GMAT and TOEFL.Is it advisable to work for an year and then apply for Phd?Which is the best book or way to prepare for GMAT?