@article {pmid21429518, title = {Infant distress at five weeks of age and caregiver frustration}, journal = {J. Pediatr.}, volume = {159}, number = {3}, year = {2011}, month = {Sep}, pages = {425{\textendash}430}, author = {Fujiwara, T. and Barr, R. G. and Brant, R. and Barr, M.} }