Hi Dr Jeckyll, Thanks for your response. Unfortunately the link isn't working at my computer. I'm still searching for literature, so tips are very welcome.

I’ll start a master thesis with the following research subject: the relation between business performance (sales) and planned hours (employees). I’ve the possibility to collect sales data of 100+ stores. Unfortunately, it’s quite a job to find useful articles in the existing literature (which lead to the research gap). Anyone some tips/recommendations about how to find these kind of articles?