diff --git a/book/basics/steel/information.ipynb b/book/basics/steel/information.ipynb
index 27179a4..325adf1 100644
--- a/book/basics/steel/information.ipynb
+++ b/book/basics/steel/information.ipynb
@@ -4,7 +4,23 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Information"
+    "# Information\n",
+    "\n",
+    "## Different sources\n",
+    "\n",
+    "  - **Internet**\n",
+    "    - [Corusconstruction](https://www.corusconstruction.com/) hot rolled and cold formed sections (blue book), composite slab floors, sheet piling, bolts, details, case studies\n",
+    "    - [Voetstalpine](https://www.voestalpine.com/sadef/en/SEO/cold-formed-profiles) cold formed profiles\n",
+    "    - [Bouwen met Staal](https://www.bouwenmetstaal.nl/) (dutch) steel profiles, links, tools\n",
+    "\n",
+    "  - **Magazines**:\n",
+    "    - Bouwen met staal (dutch): projects, materials\n",
+    "\n",
+    "  - **Books**: \n",
+    "    - Overspannend staal, Basisboek, Construeren A, B (dutch): design methods, examples and material information. Note: these books are based on the old dutch code\n",
+    "\n",
+    "  - **Search terms**:\n",
+    "    - Steel, steelprofiles, steelconstruction."
    ]
   },
   {