https://www.biopharmainstitute.com/faq/what-is-the-difference-between-single-blind-and-double-blind-clinical-trialsПо-русски:https://ru.wikipedia.org/wiki/%D0%A1%D0%BB%D0%B5%D0%BF%D0%BE%D0%B9_%D0%BC%D0%B5%D1%82%D0%BE%D0%B4