C# 5, or C# version 5.0, was released on September 12, 2012.
Here are books about C# 5.
2012-06-15
C# 5.0
Edition: 1
Series: Pocket Reference
Authors: Joseph Albahari and Ben Albahari
Publisher: O’Reilly
ISBN: 9781449320171
Type: Book
Format: Paperback
Price: US $15
On sale @ Amazon.
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2012-06-19
C# 5.0 In A Nutshell
Edition: 1
Series: The Definitive Reference
Authors: Joseph Albahari and Ben Albahari
Publisher: O’Reilly
ISBN: 9781449320102
Type: Book
Format: Paperback
Price: US $55
On sale @ Amazon.
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2012-10-00
Programming C# 5.0
Edition: 1
Series: Programming
Author: Ian Griffiths
Publisher: O’Reilly
ISBN: 9781449320416
Type: Book
Format: Paperback
Price: US $55
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2012-11-27
Essential C# 5.0
Edition: 4
Series: Windows Development
Authors: Mark Michaelis and Eric Lippert
Publisher: Pearson
ISBN: 9780321877581
Type: Book
Format: Paperback
Price: US $65
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2013-09-30
C#
Edition: 3
Series: In Depth
Author: Jon Skeet
Publisher: Manning
ISBN: 9781617291340
Type: Book
Format: Paperback
Price: US $50
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2014-06-13
Concurrency In C#
Edition: 1
Series: Cookbook
Authors: Stephen Cleary
Publisher: O’Reilly
ISBN: 9781449367565
Type: Book
Format: Paperback
Price: US $40
On sale @ Amazon.
Shop @ O’Reilly.
