Acoustic and optical phonon dynamics from femtosecond time-resolved optical spectroscopy of the superconducting iron pnictide Ca(Fe0.944Co0.056)2As2Sunil Kumar, L. Harnagea, S. Wurmehl, B. Buchner and A. K. SoodEPL, 100 5 (2012) 57007DOI: https://doi.org/10.1209/0295-5075/100/57007