However, they require massive parallel training datasets (Koehn and Knowles, 2017).
there has been extensive work on utilizing non-parallel corpora to boost the performance of SEQ2SEQ models (Sennrich et al., 2016;Gülçehre et al., 2015), mostly in neural machine translation where models that require absolutely no parallel corpora have also been pro- posed (Artetxe et al., 2018;Lample et al., 2018b).