diff --git a/Observable.js b/Observable.js
index 03545cd..0886bd2 100644
--- a/Observable.js
+++ b/Observable.js
@@ -11,12 +11,19 @@ class ObserverList {
   }
   add(observer) {
     // todo add observer to list
+    return this.observerList.push(observer);
   }
   remove(observer) {
     // todo remove observer from list
+    this.observerList = this.observerList.filter(item => item != observer);
+
   }
   count() {
     // return observer list size
+    return this.observerList.length;
+  }
+  get(index) {
+    return this.observerList[index];
   }
 }
 
@@ -26,12 +33,18 @@ class Subject {
   }
   addObserver(observer) {
     // todo add observer
+    this.observers.add(observer);
   }
   removeObserver(observer) {
     // todo remove observer
+    this.observers.remove(observer);
   }
   notify(...args) {
     // todo notify
+    let observerCount = this.observers.count();
+    for(let i=0; i<observerCount; i++) {
+      this.observers.get(i).update(...args);
+    }
   }
 }
 
diff --git a/PubSub.js b/PubSub.js
index 0c7999e..0455e66 100644
--- a/PubSub.js
+++ b/PubSub.js
@@ -13,14 +13,32 @@ module.exports = class PubSub {
 
   subscribe(type, fn) {
     // todo subscribe
+    if(typeof this.subscribers[type] === 'undefined') {
+      this.subscribers[type] = [fn];
+    } else {
+      this.subscribers[type].push(fn);
+    }
   }
 
   unsubscribe(type, fn) {
     // todo unsubscribe
+    let listener = this.subscribers[type];
+    if(!listener) {
+      return;
+    }
+    this.subscribers[type] = listener.filter(item => item != fn);
+
   }
 
   publish(type, ...args) {
     // todo publish
+    let listener = this.subscribers[type];
+    if(!listener) {
+      return;
+    }
+    listener.forEach(element => {
+      element.call(this, ...args);
+    });
   }
 
 }