Merge pull request Froussios#19 from ctranxuan/patch-1

fix(typo)

Author: Froussios

Part 4 - Concurrency/1. Scheduling and threading.md

@@ -37,7 +37,7 @@ We see here that we called `onNext` on our subject from 3 different threads. Eve
 
 ## subscribeOn and observeOn
 
-`subscribeOn` and `observeOn` allow you to control you to control the invocation of the subscription and the reception of notifications (what thread will call `onNext`/`onError`/`onCompleted` on your observer).
+`subscribeOn` and `observeOn` allow you to control the invocation of the subscription and the reception of notifications (what thread will call `onNext`/`onError`/`onCompleted` on your observer).
 
 ```java
 public final Observable<T> observeOn(Scheduler scheduler)