KOAKUTSU , T., MOROZUMI , N., HOSHIKAWA , T., OGAWA , S., ISHII , Y. and ITOI , E. (2011) “Bilateral spondylolysis of inferior articular processes of the fourth lumbar vertebra: a case report”, Upsala Journal of Medical Sciences, 117(1), pp. 72–77. doi: 10.3109/03009734.2011.629750.