1.https://towardsdatascience.com/creating-a-spell-checker-with-tensorflow-d35b23939f60
3.https://medium.com/@grammercr/benefits-of-english-grammar-correction-online-d7e0dfc586ca
4.https://medium.com/@surmenok/deep-learning-for-spell-checking-2ffdbad65554
5.https://towardsdatascience.com/deep-learning-autocorrect-product-and-technical-overview-1c219cee0698