@article{ljs21057,
 author={Abd El-basit, W.},
 year={2012},
 title={Design of a Novel System Based on 555 Timers to Automatically Sense Temperature, Force, Light, and Relative Humidity},
 journal={Leonardo J. Sci.},
 volume={11},
 number={21},
 pages={57-69},
 url={http://ljs.academicdirect.org/A21/057_069.pdf}
}