@article {liu2016exploration,
	title = {The exploration of objective task difficulty and domain knowledge effects on users{\textquoteright} query formulation},
	journal = {Proceedings of the Association for Information Science and Technology},
	volume = {53},
	number = {1},
	year = {2016},
	pages = {1{\textendash}9},
	author = {Chang Liu and Zhang, Xiangmin and Wei Huang}
}
