diff --git a/docs/courses/data-structure.md b/docs/courses/data-structure.md
index 6387018..abe1c65 100644
--- a/docs/courses/data-structure.md
+++ b/docs/courses/data-structure.md
@@ -3,6 +3,7 @@ layout: default
 title: Data-Structure
 parent: Courses
 nav_order: 11
+has_children: true
 ---
 
 # Data Structure
@@ -20,21 +21,19 @@ nav_order: 11
 
 ## Introduction
 
-# 자료 구조 (Data Structure)
-
-- [리스트](data_structure/list.md)
+- [리스트](https://github.com/boanlab/boanlab.github.io/blob/983f556286b0291107974c2d8fc5c556dc1a5e1d/docs/courses/data-structure/list.md)
 
   - 배열
   - 연결 리스트 (linked list)
   - 이중 연결 리스트 (doubly linked list)
   - 환형 연결 리스트 (circular linked list)
 
-- [스택](data_structure/stack.md)
+- [스택](https://github.com/boanlab/boanlab.github.io/blob/983f556286b0291107974c2d8fc5c556dc1a5e1d/docs/courses/data-structure/stack.md)
 
   - 배열 기반 스택
   - 연결 리스트 기반 스택
 
-- [큐](data_structure/queue.md)
+- [큐](https://github.com/boanlab/boanlab.github.io/blob/983f556286b0291107974c2d8fc5c556dc1a5e1d/docs/courses/data-structure/queue.md)
 
   - 배열 기반 큐
   - 순환 큐
@@ -44,7 +43,7 @@ nav_order: 11
     - 배열 기반 데크
     - 연결 리스트 기반 데크
 
-- [트리](data_structure/tree.md)
+- [트리](https://github.com/boanlab/boanlab.github.io/blob/983f556286b0291107974c2d8fc5c556dc1a5e1d/docs/courses/data-structure/tree.md)
 
   - 트리
 
@@ -61,7 +60,7 @@ nav_order: 11
 
   - 분리 집합
 
-- [그래프](data_structure/graph.md)
+- [그래프](https://github.com/boanlab/boanlab.github.io/blob/983f556286b0291107974c2d8fc5c556dc1a5e1d/docs/courses/data-structure/graph.md)
 
   - 그래프
   - 그래프 순회
diff --git a/docs/courses/distributed-systems.md b/docs/courses/distributed-systems.md
index e4a5952..7aa8feb 100644
--- a/docs/courses/distributed-systems.md
+++ b/docs/courses/distributed-systems.md
@@ -3,6 +3,7 @@ layout: default
 title: Distributed-Systems
 parent: Courses
 nav_order: 16
+has_children: true
 ---
 
 # Distributed Systems
@@ -20,12 +21,10 @@ nav_order: 16
 
 ## Introduction
 
-# 분산 시스템 (Distributed Systems)
-
-- [Introduction](distributed_systems/introduction.md)
-- [Architectural Styles](distributed_systems/architecture.md)
-- [Communications](distributed_systems/communication.md)
-- [Naming](distributed_systems/naming.md)
-- [Coordination](distributed_systems/coordination.md)
-- [Consistency and Replication](distributed_systems/consistency.md)
-- [Fault Tolerance](distributed_systems/fault_tolerance.md)
+- [Introduction](https://github.com/boanlab/boanlab.github.io/blob/983f556286b0291107974c2d8fc5c556dc1a5e1d/docs/courses/distributed-systems/introduction.md)
+- [Architectural Styles](https://github.com/boanlab/boanlab.github.io/blob/983f556286b0291107974c2d8fc5c556dc1a5e1d/docs/courses/distributed-systems/architecture.md)
+- [Communications](https://github.com/boanlab/boanlab.github.io/blob/983f556286b0291107974c2d8fc5c556dc1a5e1d/docs/courses/distributed-systems/communication.md)
+- [Naming](https://github.com/boanlab/boanlab.github.io/blob/983f556286b0291107974c2d8fc5c556dc1a5e1d/docs/courses/distributed-systems/naming.md)
+- [Coordination](https://github.com/boanlab/boanlab.github.io/blob/983f556286b0291107974c2d8fc5c556dc1a5e1d/docs/courses/distributed-systems/coordination.md)
+- [Consistency and Replication](https://github.com/boanlab/boanlab.github.io/blob/983f556286b0291107974c2d8fc5c556dc1a5e1d/docs/courses/distributed-systems/consistency.md)
+- [Fault Tolerance](https://github.com/boanlab/boanlab.github.io/blob/983f556286b0291107974c2d8fc5c556dc1a5e1d/docs/courses/distributed-systems/fault_tolerance.md)