Add two papers for dialogue generation.

README.md

@@ -98,6 +98,7 @@ with Neural Networks](https://papers.nips.cc/paper/5346-sequence-to-sequence-lea
 <h3 id="gan_based">Generative Adversarial Nets Based Methods</h3>
 
 * Kusner, Matt J and Hernández-Lobato, José Miguel. 2016. [GANS for Sequences of Discrete Elements with the Gumbel-softmax Distribution](https://arxiv.org/pdf/1611.04051). *arXiv preprint arXiv:1611.04051*. ([Citation](https://scholar.google.com/scholar?cites=11002066464238691420&as_sdt=2005&sciodt=0,5&hl=en): 71)
+* Li, Jiwei and Monroe, Will and Shi, Tianlin and Jean, Sébastien and Ritter, Alan and Jurafsky, Dan. 2017. [Adversarial Learning for Neural Dialogue Generation](https://www.aclweb.org/anthology/D17-1230.pdf). In *Proceedings of EMNLP 2017*. [[code](https://github.com/liuyuemaicha/Adversarial-Learning-for-Neural-Dialogue-Generation-in-Tensorflow)] ([Citation](https://scholar.google.com.hk/scholar?cites=2709411320030823497&as_sdt=2005&sciodt=0,5&hl=en): 385)
 * Gulrajani, Ishaan and Ahmed, Faruk and Arjovsky, Martin and Dumoulin, Vincent and Courville, Aaron C. 2017. [Improved Training of Wasserstein GANs](https://papers.nips.cc/paper/7159-improved-training-of-wasserstein-gans.pdf). In *Proceedings of NeurIPS 2017*. ([Citation](https://scholar.google.com/scholar?cites=3068694056154618633&as_sdt=2005&sciodt=0,5&hl=en): 1,102)
 * Yu, Lantao and Zhang, Weinan and Wang, Jun and Yu, Yong. 2017. [SeqGAN: Sequence Generative Adversarial Nets with Policy Gradient](https://www.aaai.org/ocs/index.php/AAAI/AAAI17/paper/download/14344/14489). In *Proceedings of AAAI 2017*. ([Citation](https://scholar.google.com/scholar?cites=13783508915327278077&as_sdt=2005&sciodt=0,5&hl=en): 436)
 * Liang, Xiaodan and Hu, Zhiting and Zhang, Hao and Gan, Chuang and Xing, Eric P. 2017. [Recurrent Topic-Transition GAN for Visual Paragraph Generation](http://openaccess.thecvf.com/content_ICCV_2017/papers/Liang_Recurrent_Topic-Transition_GAN_ICCV_2017_paper.pdf). In *Proceedings of IEEE 2017*. ([Citation](https://scholar.google.com/scholar?cites=7127182007926953895&as_sdt=2005&sciodt=0,5&hl=en): 65)
@@ -113,6 +114,7 @@ with Neural Networks](https://papers.nips.cc/paper/5346-sequence-to-sequence-lea
 
 <h3 id="rl_based">Reinforcement Learning Based Methods</h3>
 
+* Li, Jiwei and Monroe, Will and Ritter, Alan and Galley, Michel and Gao, Jianfeng and Jurafsky, Dan. 2016. [Deep Reinforcement Learning for Dialogue Generation](https://www.aclweb.org/anthology/D16-1127.pdf). In *Proceedings of EMNLP 2016*. [[code](https://github.com/liuyuemaicha/Deep-Reinforcement-Learning-for-Dialogue-Generation-in-tensorflow)] ([Citation](https://scholar.google.com.hk/scholar?cites=1196225117608418887&as_sdt=2005&sciodt=0,5&hl=en): 500)
 * Lin, Kevin and Li, Dianqi and He, Xiaodong and Zhang, Zhengyou and Sun, Ming-Ting. 2017. [Adversarial Ranking for Language Generation](http://papers.nips.cc/paper/6908-adversarial-ranking-for-language-generation.pdf). In *Proceedings of NeurIPS 2017*. ([Citation](https://scholar.google.com/scholar?cites=6871069604642164772&as_sdt=2005&sciodt=0,5&hl=en): 54)
 * Che, Tong and Li, Yanran and Zhang, Ruixiang and Hjelm, R Devon and Li, Wenjie and Song, Yangqiu and Bengio, Yoshua. 2017. [Maximum-Likelihood Augmented Discrete Generative Adversarial Networks](https://arxiv.org/pdf/1702.07983). *arXiv preprint arXiv:1702.07983*. ([Citation](https://scholar.google.com/scholar?cites=15378466307857672293&as_sdt=2005&sciodt=0,5&hl=en): 64)
 * Xu, Jingjing and Zhang, Yi and Zeng, Qi and Ren, Xuancheng and Cai, Xiaoyan and Sun, Xu. 2018. [A Skeleton-Based Model for Promoting Coherence Among Sentences in Narrative Story Generation](https://arxiv.org/pdf/1808.06945). In *Proceedings of EMNLP 2018*. ([Citation](https://scholar.google.com/scholar?cites=12919425531135632296&as_sdt=2005&sciodt=0,5&hl=en): 4)