Research according to the IMP-tradition has a strong foundation in case studies. These case studies are often built on interviews. Whereas interviews may capture the complexity of business relationships and networks, they are associated with weaknesses, especially if the interviews are meant to capture events that occurred in the past. In this paper we challenge the one-sided use of interviews through proposing alternative data sources for studies on business network dynamics. The purpose of this paper is to discuss and exemplify how press releases, newspaper articles and annual reports can be used systematically to study business network dynamics. Examples from three ongoing studies using these sources are presented to illustrate their use. These studies indicate that press releases, annual reports and newspaper articles enable both cross-sectional and longitudinal studies of business network dynamics, where the systematic use of data enables the capturing of a network at different times of its development without the risk of rationalisation or loss of memory effects.