BibTex format
@inproceedings{Sheppard:1999:10.1117/12.346824,
author = {Sheppard, CJR and Török, P},
doi = {10.1117/12.346824},
pages = {458--472},
publisher = {SPIE-INT SOC OPTICAL ENGINEERING},
title = {Effects of Fresnel number in focusing and imaging},
url = {http://dx.doi.org/10.1117/12.346824},
year = {1999}
}