Collecting grey literature remains a challenge to library and information science (LIS) professionals. Grey items such as reports, proceedings, or working papers cannot be purchased or bought like journals and books. There is no special agency or supplier for grey materials. Buying information is part of the traditional library role, together with gateway and archive functions. In line with the economic definition of grey literature, "material that usually is available through specialized channels and may not enter normal channels (...) of (...) distribution", one comes to understand that a systematic collection of grey literature calls on specific attention, competency, and procedures.