Forum:The Real Names of the Hokages, where did someone get it?

According to the recent Hokage article, there exist real names (not hokage titles) for each Hokage. For the First Hokage, it is Hashirama Senju. We all know atht because it has been release in the manga. For the Fourth Hokage and Fifth Hokage, namely Minato Namikaza and Tsunade, they are also stated in the manga.

But what about Second and Third Hokage's names, where did they come from? Can someone show to me the exact references for these names because it bothers me very much. Moreover, if someone got it from a Naruto manual or character manual, you can show to me the original form and the translated version.

Second Hokage's name is Tobirama Senju and Third Hokage's name is Hiruzen Sarotobi. It is important for us not to be mislead.

(You can directly answer me, by putting the right reference/s in the Hokage article itself.)