насколько нам известно
• To our knowledge (or To the best of our knowledge, or As far as we know, or So far as we know) such methods have never-been employed.
Источник:
Русско-английский научно-технический словарь
на Gufo.me
• To our knowledge (or To the best of our knowledge, or As far as we know, or So far as we know) such methods have never-been employed.