Original: She participated in a Pablo Casals masterclass in Zermatt, Switzerland in 1960, and undertook short-term studies with Paul Tortelier in Paris in 1962 and Mstislav Rostropovich in Russia in 1966.
Simplified: She took part in a masterclass with Pablo Casals in Zermatt, Switzerland in 1960, and had some lessons with Paul Tortelier in Paris in 1962, and with Mstislav Rostropovich in Russia in 1966.