Update 'mathematics.md'

mathematics.md

@@ -10,6 +10,7 @@ THEORY OF COMPUTABLE FIELDS - Rabin](https://www.ams.org/journals/tran/1960-095-
 - [BGP Protocol](https://en.wikipedia.org/wiki/Border_Gateway_Protocol)
 - [Internet Exchange Point](https://en.wikipedia.org/wiki/Internet_exchange_point)
 - [BCM4352 Windows driver on Linux](https://help.ubuntu.com/community/WifiDocs/Driver/Ndiswrapper)
+- [Yusha Kobo](https://shop.yushakobo.jp/en)
 
 
 #  Mathematics