1. Albattah Mohammed Marco Giron Paul Goodrum Daniel Groves Dean Hamrick Hossein Karimi and Tim Taylor. 2015. Is There a Demographic Craft Labor Cliff That Will Affect Project Performance? Construction Industry Institute. https://www.construction-institute.org/scriptcontent/more/318_1_more.cfm.
2. Frank J. A. & Kapila V. (2017). Mixed-reality learning environments: Integrating mobile interfaces with laboratory test-beds. Computers & Education 110 88–104. https://doi.org/10.1016/j.compedu.2017.02.00910.1016/j.compedu.2017.02.009
3. Henderson R. (2015). Industry employment and output projections to 2024. Monthly Labor Review. https://doi.org/10.21916/mlr.2015.4710.21916/mlr.2015.47
4. Labor force projections to 2024: the labor force is growing but slowly : Monthly Labor Review: U.S. Bureau of Labor Statistics. (n.d.). Retrieved July 26 2017 from https://www.bls.gov/opub/mlr/2015/article/labor-force-projections-to-2024-1.htm