Русский ⇄ Английский +

продолжительное исследование ударения
науч.-ис.	extended research (Ivan Pisarev); prolonged investigation (Ivan Pisarev); longitudinal research (Ivan Pisarev); extended study (Ivan Pisarev); continuous study (Ivan Pisarev); follow-up study (Ivan Pisarev); persistent investigation (Ivan Pisarev); panel study (Ivan Pisarev); multi-year study (Ivan Pisarev); prolonged analysis (Ivan Pisarev); marathon study (Ivan Pisarev); extended research project (Ivan Pisarev)
ОТиТБ.	longitudinal study; long-term study