In the anime, after training in the Hyperbolic Time Chamber for a week and managing to have Gotenks achieve Super Saiyan 3, Trunks states that he and Goten have become more than twice as strong as before.
That is what is found on the Trunks article on both this and the regular Dragon Ball fandom wiki. But I cannot find anything backing this up. It has some serious implications for the power of Goten and Trunks, so if you know anything could you please show me?
Thank you