Bismarck's quote

[mavisol]

I am looking for a more or less "standard" English rendition of a Bismarck's quote, the phrase I have only in Russian now. So in my awkward back translation from the Russian (which is supposedly a translation from the German) it sounds like this "Only one person should be responsible for the fulfillment of any one particular assignment."
I haven't found the phrase on the usuaul quote sites.