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When to call GC.Collect() http://blogs.msdn.com/ricom/archive/2004/11/29/271829.aspx
Two things to avoid for better memory usage http://blogs.msdn.com/ricom/archive/2003/12/02/40780.aspx
Garbage Collection: Automatic Memory Management in the Microsoft .NET Framework http://msdn.microsoft.com/en-us/magazine/bb985010.aspx
Garbage Collection Part 2: Automatic Memory Management in the Microsoft .NET Framework http://msdn.microsoft.com/en-us/magazine/bb985011.aspx