C# 5.0 was released on September 12, 2012.
Here are books about C# 5.
2012-11-27
Essential C# 5.0
Edition: 4
Series: Windows Development
Author: Mark Michaelis
Publisher: Pearson
ISBN: 9780321877581
Type: Book
Format: Paperback
Price: US $65
On sale @ Amazon.
Shop @ Pearson.
2013-09-30
C#
Edition: 3
Series: In Depth
Author: Jon Skeet
Publisher: Manning
ISBN: 9781617291340
Type: Book
Format: Paperback
Price: US $50
On sale @ Amazon.
Shop @ Manning.
