Simplify the following text for a Grade 5 native English-speaking person.
Original: The earliest international surveys of this book are the ones of Russian S. Troicky ( as of the 1949 year - see the link ) and of Swede O. Neumann .
Simplified: The earliest surveys of this book are the ones of Russian S. Troicky ( as of the 1949 year - see the link ) and of Swede O. Neumann .