If you are looking for a way to turn that search query into a proper, natural-sounding sentence in Russian, here are a few ways to phrase it depending on what you need:
"Я хочу скачать книгу про трансформаторы." (I want to download a book about transformers.) kniga transformatory skachat
"Поиск и загрузка литературы по трансформаторам." (Search and download of literature on transformers.) If you are looking for a way to
"Скачать книгу: Трансформаторы." (Download book: Transformers.) natural-sounding sentence in Russian
"Где можно скачать книгу о трансформаторах?" (Where can I download a book about transformers?)