diff --git a/package/samplers/demo/README.md b/package/samplers/demo/README.md
index 996db37b..58e84695 100644
--- a/package/samplers/demo/README.md
+++ b/package/samplers/demo/README.md
@@ -15,4 +15,4 @@ license: 'MIT License'
 module = optunahub.load_module("samplers/demo")
 sampler = module.DemoSampler(seed=42)
 ```
-See `example.py <example.py>`_ for more details.
+See [`example.py`](https://github.com/optuna/optunahub-registry/blob/main/package/samplers/demo/example.py) for more details.
diff --git a/package/samplers/evo_merge/README.md b/package/samplers/evo_merge/README.md
index 47cfaa7d..d4f04dff 100644
--- a/package/samplers/evo_merge/README.md
+++ b/package/samplers/evo_merge/README.md
@@ -35,7 +35,7 @@ for _ in range(100):
 
 print(study.trials_dataframe(attrs=("number", "value")))
 ```
-See `example.py` for a full example. You need GPU with 16G VLAM to run this example.
+See [`example.py`](https://github.com/optuna/optunahub-registry/blob/main/package/samplers/evo_merge/example.py) for a full example. You need GPU with 16G VLAM to run this example.
 The following figures are obtained from the analysis of the optimization.
 ![History Plot](images/history.png "History Plot")
 ![Parallel Coordinate Plot](images/parallel_coordinate.png "Parallel Coordinate Plot")
diff --git a/package/samplers/simple/README.md b/package/samplers/simple/README.md
index 96aecdc1..33b2be4b 100644
--- a/package/samplers/simple/README.md
+++ b/package/samplers/simple/README.md
@@ -17,7 +17,7 @@ class UserDefinedSampler(
 ):
     ...
 ```
-See `example.py <example.py>`_ for more details.
+See [`example.py`](https://github.com/optuna/optunahub-registry/blob/main/package/samplers/simple/example.py) for more details.
 
 ## Others
 This package provides an easy sampler base class to implement custom samplers.
diff --git a/package/samplers/simulated_annealing/README.md b/package/samplers/simulated_annealing/README.md
index df6c9ce3..30237f78 100644
--- a/package/samplers/simulated_annealing/README.md
+++ b/package/samplers/simulated_annealing/README.md
@@ -15,7 +15,7 @@ license: 'MIT License'
 mod = optunahub.load_module("samplers/simulated_annealing")
 sampler = mod.SimulatedAnnealingSampler()
 ```
-See `example.py` for more details.
+See [`example.py`](https://github.com/optuna/optunahub-registry/blob/main/package/samplers/simulated_annealing/example.py) for more details.
 
 ## Others
 This package provides a sampler based on Simulated Annealing algorithm.
diff --git a/package/visualization/plot_hypervolume_history_with_rp/README.md b/package/visualization/plot_hypervolume_history_with_rp/README.md
index 649459a4..a3d821c1 100644
--- a/package/visualization/plot_hypervolume_history_with_rp/README.md
+++ b/package/visualization/plot_hypervolume_history_with_rp/README.md
@@ -15,7 +15,7 @@ license: 'MIT License'
 mod = optunahub.load_module("visualization/plot_hypervolume_history_with_rp")
 mod.plot_hypervolume_history(study, reference_point)
 ```
-See `example.py <example.py>`_ for more details.
+See [`example.py`](https://github.com/optuna/optunahub-registry/blob/main/package/visualization/plot_hypervolume_history_with_rp/example.py) for more details.
 The example of generated image is as follows.
 
 ![Example](images/example.png "Example")