diff --git a/README.md b/README.md
index 13dd3bc0f8f274c7d1886c2e4d1e4939558cc046..de35fa548a368a80cb16bb79f70a9771f67f0eb0 100644
--- a/README.md
+++ b/README.md
@@ -102,3 +102,13 @@ Without any separation between Service and Repository, all of the workload of th
 Postman is a powerful tool that allows us to test our API endpoints easily. It provides a user-friendly interface to send HTTP requests and view the responses, errors, and status codes.
 
 #### Reflection Publisher-3
+> Observer Pattern has two variations: Push model (publisher pushes data to subscribers) and Pull model (subscribers pull data from publisher). In this tutorial case, which variation of Observer Pattern that we use?
+
+In this case, we used the Push Model, indicated by the fact that the publisher sends notifications to subscribers whenever a new product is created or deleted. The subscribers do not need to request the data; they receive it automatically when the publisher sends it.
+
+> What are the advantages and disadvantages of using the other variation of Observer Pattern for this tutorial case? (example: if you answer Q1 with Push, then imagine if we used Pull)
+
+The Pull model has its own advantages and disadvantages. One advantage is that it allows subscribers to control when they want to receive updates, which can be useful in certain scenarios. However, this can also lead to increased complexity, as subscribers need to implement their own logic to pull data from the publisher. Additionally, it may result in delays in receiving updates, as subscribers may not always be checking for new data.
+
+> Explain what will happen to the program if we decide to not use multi-threading in the notification process.
+If we do not use multi-threading in the notification process, the program will become blocked while waiting for each notification to be sent. This means that if one subscriber takes a long time to respond, all other subscribers will also be delayed. This can lead to a poor user experience and may cause timeouts or errors if the notification process takes too long.
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diff --git a/src/service/product.rs b/src/service/product.rs
index 6bf566600e9fc6adb3a04447beffae1cc3ed6016..d8e0540a2c4d897ecfe4611daff5c8a6d116af51 100644
--- a/src/service/product.rs
+++ b/src/service/product.rs
@@ -5,7 +5,7 @@ use bambangshop::{Result, compose_error_response};
 use crate::model::product::Product;
 use crate::repository::product::ProductRepository;
 
-use super::notification::NotificationService;
+use crate::service::notification::NotificationService;
 
 pub struct ProductService;