Часть их работ - это уникальная кол

Часть их работ - это уникальная коллекция, сохранившаяся в музее естественной истории Гарвардского университета.

Results (English) 1:

Part of their work is a unique collection, preserved in the Museum of natural history at Harvard University.

Results (English) 2:

Part of their work - is a unique collection, which is preserved in the Museum of Natural History at Harvard University.

Results (English) 3:

Part of their work - it is a unique collection, preserved in the museum of natural history of Harvard University.