diff --git a/content/research/_index.md b/content/research/_index.md
index a45b5bb..306be92 100644
--- a/content/research/_index.md
+++ b/content/research/_index.md
@@ -3,17 +3,3 @@ title = "Research Notes"
transparent = false
sort_by = "weight"
+++
-
-
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{{ section.title }}
-
-
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diff --git a/content/research/java.md b/content/research/java.md
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+++ b/content/research/java.md
@@ -0,0 +1,6 @@
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+title = "Java"
+weight = 106
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+
+- [Abstract Classes Resolution Order](@/research/java/abstract.md)
diff --git a/content/research/java/abstract.md b/content/research/java/abstract.md
new file mode 100644
index 0000000..30e89e0
--- /dev/null
+++ b/content/research/java/abstract.md
@@ -0,0 +1,3 @@
++++
+title = "Java: Abstract Classes Resolution Order"
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diff --git a/content/research/sql.md b/content/research/sql.md
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+++ b/content/research/sql.md
@@ -0,0 +1,14 @@
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+title = "SQL"
+weight = 115
++++
+
+- [Cross Join](@/research/sql/cross-join.md)
+- [Except](@/research/sql/except.md)
+- [Fetch First](@/research/sql/fetch-first.md)
+- [Inner Join](@/research/sql/inner-join.md)
+- [Join Using](@/research/sql/join-using.md)
+- [Left Join](@/research/sql/left-join.md)
+- [Right Join](@/research/sql/right-join.md)
+- [Row_Number()](@/research/sql/row_number.md)
+- [Select Over](@/research/sql/over.md)
diff --git a/content/research/sql/cross-join.md b/content/research/sql/cross-join.md
new file mode 100644
index 0000000..bf2c91e
--- /dev/null
+++ b/content/research/sql/cross-join.md
@@ -0,0 +1,3 @@
++++
+title = "SQL: Cross Join"
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diff --git a/content/research/sql/except.md b/content/research/sql/except.md
new file mode 100644
index 0000000..12a0428
--- /dev/null
+++ b/content/research/sql/except.md
@@ -0,0 +1,3 @@
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+title = "SQL: Select Except"
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diff --git a/content/research/sql/fetch-first.md b/content/research/sql/fetch-first.md
new file mode 100644
index 0000000..5c79dae
--- /dev/null
+++ b/content/research/sql/fetch-first.md
@@ -0,0 +1,4 @@
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+title = "SQL: Fetch First"
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+
diff --git a/content/research/sql/inner-join.md b/content/research/sql/inner-join.md
new file mode 100644
index 0000000..e5ebdd5
--- /dev/null
+++ b/content/research/sql/inner-join.md
@@ -0,0 +1,3 @@
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+title = "SQL: Inner Join"
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diff --git a/content/research/sql/join-using.md b/content/research/sql/join-using.md
new file mode 100644
index 0000000..2a4cfac
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+++ b/content/research/sql/join-using.md
@@ -0,0 +1,3 @@
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+title = "Join Using"
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diff --git a/content/research/sql/left-join.md b/content/research/sql/left-join.md
new file mode 100644
index 0000000..1d30ea6
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+++ b/content/research/sql/left-join.md
@@ -0,0 +1,3 @@
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+title = "SQL: Left Join"
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diff --git a/content/research/sql/over.md b/content/research/sql/over.md
new file mode 100644
index 0000000..c194283
--- /dev/null
+++ b/content/research/sql/over.md
@@ -0,0 +1,3 @@
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+title = "SQL: Select Over"
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diff --git a/content/research/sql/right-join.md b/content/research/sql/right-join.md
new file mode 100644
index 0000000..30b4a57
--- /dev/null
+++ b/content/research/sql/right-join.md
@@ -0,0 +1,3 @@
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+title = "SQL: Right Join"
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diff --git a/content/research/sql/row_number.md b/content/research/sql/row_number.md
new file mode 100644
index 0000000..dc3e557
--- /dev/null
+++ b/content/research/sql/row_number.md
@@ -0,0 +1,5 @@
++++
+title = "SQL: Function `row_number`"
++++
+
+