Izvori tekstova 

Što je sinkro?-https://en.wikipedia.org/wiki/Svetlana_Romashina 

Natalia Ishchenko-https://en.wikipedia.org/wiki/Natalia_Ishchenko 

Anastasia Davydova-https://en.wikipedia.org/wiki/Anastasia_Davydova 

Svetlana Romashina-https://en.wikipedia.org/wiki/Svetlana_Romashina