Complex sentence: Then, at the age of 29, he Doyle Dane Bernbach.W ith the exception of a few years in the early 1970's when he attempted to start his own agency, he would spend his entire career there.
Split into simpler sentences: Then, at the age of 29, he began to work for Doyle Dane Bernbach. With the exception of a few years in the early 1970's when he attempted to start his own agency, he would spend his entire career there.