@article{Romero2011b, 
author = {Mac\ias-Romero, C. and Foreman, M. R. and T\"{o}r\"{o}k, P.}, 
journal = {Opt. Express}, 
pages = {25077--25083}, 
title = {Spatial and temporal variations in vector fields}, 
volume = {19}, 
year = {2011},
doi = {10.1364/OE.19.025066},
}