Complex sentence: In 2000 from 19 August to 19 October John Perceval Retrospective Exhibition was held in Galeria Aniela Fine Art Gallery and Sculpture Park officially opened by the Chairman of Sotheby's (included 80 oil paintings and works on paper from 1946 to 1999).
Split into simpler sentences: In 2000 from 19 August to 19 October "John Perceval Retrospective Exhibition" was held in Galeria Aniela Fine Art Gallery and Sculpture Park. It was officially opened by the Chairman of Sotheby's (it included 80 oil paintings and works on paper from 1946 to 1999).