added reference dll not being moved to server when website project published

I have a website project to which I have added references to Microsoft.SqlServer.DTSRuntimeWrap and Microsoft.SqlServer.ManagedDTS .  My understanding is that when the site gets published to the server the referenced dll s should get moved into the bin folder in \inetpub\sitename .  This does not appear to be happening - the dlls cannot  be found at runtime and when the button is operated that would cause them to be accessed.

The site operates fine if I access it through debug from my vs 2012 .

Could someone tell me what might be wrong? 

Thanks much in advance for any help, Roscoe