Before revision:  Experimental results on English-German and  English-Vietnamese low resource neural machine translation showed that the proposed approach outperforms baselines that use the traditional back-translation method .
After revision:  Experimental results on English-German and English-Vietnamese backward translation models by 11.06 and 1.5 BLEUs respectively. The synthetic data generated by the improved English-German backward model was used to train a forward model which out-performed another forward model trained using standard back-translation method .