efficacy russian
си́ла
power, might, strength, force
vigor, vigour, intensity
energy, efficacy, ability
де́йствие
action, activity, operation, act
effect, influence, impact
efficacy, valitity
эффекти́вность
effectiveness, efficiency, efficacy, efficaciousness
де́йственность
effectiveness, efficacy, activity, effectualness
радика́льность
radicalism, efficacy