@article{Crowdy&Marshall_2006_JFM,
title = {The motion of a point vortex through gaps in walls},
author = {D. G. Crowdy and J. S. Marshall},
pages = {31--48.},
year = 2006,
journal = {J. Fluid Mech.},
volume = 551,
url = {http://archipelago.uma.pt/pdf_library/Crowdy\&Marshall_2006_JFM.pdf}
}