NuGet Package Manager installing System dlls

Question

I have installed a 3rd Party .Net library https://github.com/Quobject/SocketIoClientDotNet using NuGet Package manager like so:

Install-Package SocketIoClientDotNet

I have noticed that this has imported several custom dlls as well as many .NET dlls such as:

  System.Collections.Immutable
  System.Collections.Specialized
  System.Linq
  System.Net.NameResolution
  System.Net.Security
  System.Net.Sockets
  System.Runtime.Extensions
  System.Runtime.InteropServices
  System.Security.Cryptography.Algorithms
  System.Security.Cryptography.Encoding
  System.Security.Cryptography.Primitives
  System.Security.Cryptography.X509Certificates
  System.Text.RegularExpressions
  System.Threading
  System.Threading.Timer

I see that these dlls all have been imported into a folder called 'packages' in my solutions directory.

I do not want to have to include all these files in my installer so I was thinking that because these are system .NET dlls, can I not simply add them manually myself (Right Click-->Add Reference) and forget about them being pulled in via the package manager?

BUT when I try to add them using Visual Studios 'Add Reference' I do not see many of them in Assemblies-Framework or Assemblies-Extensions.