Before revision:  Experiments have shown that the method outperforms both the standard back-translation and self-learning approach on IWSLT'14 English German low resource NMT. While the method also outperforms the iterative back-translation , though slightly, the number of models required to be trained is reduced exactly by the number of iterations .
After revision:  Experiments have shown that the method outperforms both the standard back-translation method on English-German low resource neural machine translation. We also proposed an iterative self-learning approach that outperforms the iterative back-translation , though slightly, the number of models required to be trained is reduced exactly by the number of iterations .