Evaluation of the usefulness of the new composition of gel for ultrasonographic diagnostic examinations - Kęcik, Tadeusz; Lewandowski, Paweł; Portacha, Lidia; Waszczuk, Tomasz; Marchlewska, Barbara; Pacak, Izabela (Klinika Oczna / Acta Ophthalmologica Polonica, 1993)