diff --git a/Observable.js b/Observable.js
index 03545cd..639eb0c 100644
--- a/Observable.js
+++ b/Observable.js
@@ -7,31 +7,37 @@
 
 class ObserverList {
   constructor() {
-    this.observerList = [];
+    this.observerList = []
   }
   add(observer) {
-    // todo add observer to list
+    return this.observerList.push(observer)
   }
   remove(observer) {
-    // todo remove observer from list
+    for(var i=0,len=this.count();i<len;i++)
+      if(this.observerList[i]===observer)
+        return this.observerList.splice(i, 1)
   }
   count() {
-    // return observer list size
+    return this.observerList.length
+  }
+  get(i){
+    return this.observerList[i]
   }
 }
 
 class Subject {
   constructor() {
-    this.observers = new ObserverList();
+    this.observers = new ObserverList()
   }
   addObserver(observer) {
-    // todo add observer
+    this.observers.add(observer)
   }
   removeObserver(observer) {
-    // todo remove observer
+    this.observers.remove(observer)
   }
   notify(...args) {
-    // todo notify
+    for (var i = 0, len = this.observers.count(); i < len; i++)
+      this.observers.get(i).update(...args)
   }
 }
 
diff --git a/PubSub.js b/PubSub.js
index 0c7999e..3caf4bd 100644
--- a/PubSub.js
+++ b/PubSub.js
@@ -12,15 +12,37 @@ module.exports = class PubSub {
   }
 
   subscribe(type, fn) {
-    // todo subscribe
+    if (!this.subscribers[type]) {
+      this.subscribers[type] = [];
+    }
+    this.subscribers[type].push(fn);
   }
 
   unsubscribe(type, fn) {
-    // todo unsubscribe
+    for (var type in this.subscribers) {
+      if (this.subscribers[type]) {
+        for (var i = 0, j = this.subscribers[type].length; i < j; i++) {
+          if (this.subscribers[type][i] === fn) {
+            this.subscribers[type].splice(i, 1);
+          }
+        }
+      }
+    }
+    return this;
   }
 
   publish(type, ...args) {
-    // todo publish
+    if (!this.subscribers[type]) {
+      return false;
+    }
+    var subscribers = this.subscribers[type],
+        len = subscribers ? subscribers.length : 0;
+
+    while (len--) {
+      subscribers[len].call(type, ...args);
+    }
+
+    return this;
   }
 
 }