@article {DeutchFGH18,
	title = {NLProveNAns: Natural Language Provenance for Non-Answers},
	journal = {Proc. VLDB Endow.},
	volume = {11},
	number = {12},
	year = {2018},
	pages = {1986{\textendash}1989},
	author = {Daniel Deutch and Nave Frost and Amir Gilad and Tomer Haimovich}
}
