How it is correct: "doors" or "doors"?

In Russian there are many difficult cases of writingand pronunciation. From their number it is possible to select the noun of the third declension of the "door", standing in the instrumental plural. Still, how correctly: "doors" or "doors"? Let's say at once that both of these options are correct. However, the use of the form "doors" is still preferable. In Russian, I must say, there are two more nouns, which in the instrumental plural are also used in two variants. This: "horses" and "horses", "daughters" and "daughters." In all other cases, the nouns of the third declension in the instrumental plural are end-uses.