Сегодня я прочитал в книге предложение:
"Он работает над статьей "Общественный Транспорт или личный автомобиль""
I was wondering how will be to say:
1. I work on a research about mutul funds / I am writing a research on mutua funds.
2. I have wrote many researches on "the fluctations of the price of gold"
3. My main scientific interest is "International Trade".