Description: Microsoft' s own official blog, TAPI3.x structure of its own library Atapi, containing the source code, almost covers all the features!
File list (Check if you may need any files):
Phone
.....\ActiveCallForm.cs
.....\ActiveCallForm.Designer.cs
.....\ActiveCallForm.resx
.....\bin
.....\...\Debug
.....\...\.....\Atapi.dll
.....\...\.....\Atapi.pdb
.....\...\.....\Atapi.xml
.....\...\.....\Phone.exe
.....\...\.....\Phone.pdb
.....\...\.....\Phone.vshost.exe
.....\...\.....\Phone.vshost.exe.manifest
.....\...\Release
.....\...\.......\app.publish
.....\...\.......\...........\Application Files
.....\...\.......\...........\.................\Phone_1_0_0_0
.....\...\.......\...........\.................\.............\Atapi.dll.deploy
.....\...\.......\...........\.................\.............\Phone.exe.deploy
.....\...\.......\...........\.................\.............\Phone.exe.manifest
.....\...\.......\...........\Phone.application
.....\...\.......\...........\setup.exe
.....\...\.......\Atapi.dll
.....\...\.......\Atapi.pdb
.....\...\.......\Atapi.xml
.....\...\.......\Phone.application
.....\...\.......\Phone.exe
.....\...\.......\Phone.exe.manifest
.....\...\.......\Phone.pdb
.....\...\.......\Phone.vshost.exe
.....\ForwardInfoForm.cs
.....\ForwardInfoForm.Designer.cs
.....\ForwardInfoForm.resx
.....\GetDialableNumberForm.cs
.....\GetDialableNumberForm.Designer.cs
.....\GetDialableNumberForm.resx
.....\MainForm.cs
.....\MainForm.Designer.cs
.....\MainForm.resx
.....\obj
.....\...\Debug
.....\...\.....\Phone.ActiveCallForm.resources
.....\...\.....\Phone.csproj.FileListAbsolute.txt
.....\...\.....\Phone.csproj.GenerateResource.Cache
.....\...\.....\Phone.exe
.....\...\.....\Phone.ForwardInfoForm.resources
.....\...\.....\Phone.GetDialableNumberForm.resources
.....\...\.....\Phone.MainForm.resources
.....\...\.....\Phone.pdb
.....\...\.....\Phone.Properties.Resources.resources
.....\...\.....\Phone.SelectCallForm.resources
.....\...\.....\Refactor
.....\...\.....\ResolveAssemblyReference.cache
.....\...\.....\TempPE
.....\...\.....\......\Properties.Resources.Designer.cs.dll
.....\...\Phone.csproj.FileList.txt
.....\...\Release
.....\...\.......\Phone.ActiveCallForm.resources
.....\...\.......\Phone.application
.....\...\.......\Phone.csproj.FileListAbsolute.txt
.....\...\.......\Phone.csproj.GenerateResource.Cache
.....\...\.......\Phone.exe
.....\...\.......\Phone.exe.manifest
.....\...\.......\Phone.ForwardInfoForm.resources
.....\...\.......\Phone.GetDialableNumberForm.resources
.....\...\.......\Phone.MainForm.resources
.....\...\.......\Phone.pdb
.....\...\.......\Phone.Properties.Resources.resources
.....\...\.......\Phone.SelectCallForm.resources
.....\...\.......\Refactor
.....\...\.......\ResolveAssemblyReference.cache
.....\...\.......\TempPE
.....\...\.......\......\Properties.Resources.Designer.cs.dll
.....\Phone.csproj
.....\Phone.csproj.user
.....\Phone.csproj.vspscc
.....\Phone.suo
.....\Phone_TemporaryKey.pfx
.....\Program.cs
.....\Properties
.....\..........\AssemblyInfo.cs
.....\..........\DataSources
.....\..........\Resources.Designer.cs
.....\..........\Resources.resx
.....\..........\Settings.Designer.cs
.....\..........\Settings.settings
.....\SelectCallForm.cs
.....\SelectCallForm.Designer.cs
.....\SelectCallForm.resx