I have stimulsoft reports ultimate 2014.3 and stimulsoft reports .net 2015.1 .there isn't Referenced Assemblies option in section Report : Report in none of them and I can't add any .dll file to my report :(
You can create and edit reports in the edit view of the Report Editor. The Stimulsoft Reports.Ultimate Report Designer is integrated into the edit view. You can find accurate descriptions and the functionality of individual components in the Stimulsoft online help (www.stimulsoft.com).