A Strong Approximation Theorem for Quasi-associated Sequences

By combining the Csörg..Révész quantile transform methods and the Skorohod.Strassen martingale embedding theorem, we prove a strong approximation theorem for quasi-associated random variables with mean zero and finite (2+.)th moment under polynomial decay rate. As a consequence, the decay rate for a strong approximation theorem of associated sequences of Yu (1996) is weakened.