@article {48,
	title = {Signal Propagation Techniques for Wireless Underground Communication Networks},
	journal = {Physical Communication Journal (Elsevier)},
	volume = {2},
	year = {2009},
	month = {Sept. 2009},
	pages = {167-183},
	chapter = {167},
	attachments = {http://cse.unl.edu/~cpn/system/files/UG_Signal.pdf},
	author = {I. F. Akyildiz and Z. Sun and Mehmet C. Vuran}
}
