diff --git a/gklearn/kernels/__init__.py b/gklearn/kernels/__init__.py
index c986891..7b15d70 100644
--- a/gklearn/kernels/__init__.py
+++ b/gklearn/kernels/__init__.py
@@ -18,3 +18,13 @@ from gklearn.kernels.structural_sp import StructuralSP
 from gklearn.kernels.path_up_to_h import PathUpToH
 from gklearn.kernels.treelet import Treelet
 from gklearn.kernels.weisfeiler_lehman import WeisfeilerLehman, WLSubtree
+
+# old version.
+from gklearn.kernels.commonWalkKernel import commonwalkkernel
+from gklearn.kernels.marginalizedKernel import marginalizedkernel
+from gklearn.kernels.randomWalkKernel import randomwalkkernel
+from gklearn.kernels.spKernel import spkernel
+from gklearn.kernels.structuralspKernel import structuralspkernel
+from gklearn.kernels.untilHPathKernel import untilhpathkernel
+from gklearn.kernels.treeletKernel import treeletkernel
+from gklearn.kernels.weisfeilerLehmanKernel import weisfeilerlehmankernel
\ No newline at end of file
diff --git a/gklearn/utils/__init__.py b/gklearn/utils/__init__.py
index 149a3af..7c120f3 100644
--- a/gklearn/utils/__init__.py
+++ b/gklearn/utils/__init__.py
@@ -24,3 +24,4 @@ from gklearn.utils.utils import SpecialLabel, dummy_node, undefined_node, dummy_
 from gklearn.utils.utils import normalize_gram_matrix, compute_distance_matrix
 from gklearn.utils.trie import Trie
 from gklearn.utils.knn import knn_cv, knn_classification
+from gklearn.utils.model_selection_precomputed import model_selection_for_precomputed_kernel