diff --git a/2. LangChain.ipynb b/2. LangChain.ipynb
index 9d29794..fcecc62 100644
--- a/2. LangChain.ipynb	
+++ b/2. LangChain.ipynb	
@@ -584,7 +584,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "with_message_history = RunnableWithMessageHistory(model, get_session_history)"
+    "with_message_history = RunnableWithMessageHistory(model_a, get_session_history)"
    ]
   },
   {
@@ -723,7 +723,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "chain = prompt | model | parser"
+    "chain = prompt | model_a | parser"
    ]
   },
   {
diff --git a/3. Information Processing.ipynb b/3. Information Processing.ipynb
index cdd5369..92ec61a 100644
--- a/3. Information Processing.ipynb	
+++ b/3. Information Processing.ipynb	
@@ -116,7 +116,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "plt.style.use('./d4sci.mplstyle')"
+    "plt.style.use('d4sci.mplstyle')"
    ]
   },
   {
diff --git a/4. ChatBots.ipynb b/4. ChatBots.ipynb
index 0422a19..cc38a1f 100644
--- a/4. ChatBots.ipynb	
+++ b/4. ChatBots.ipynb	
@@ -117,7 +117,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "plt.style.use('./d4sci.mplstyle')"
+    "plt.style.use('d4sci.mplstyle')"
    ]
   },
   {
@@ -169,8 +169,8 @@
    "outputs": [],
    "source": [
     "text_splitter = CharacterTextSplitter(\n",
-    "    chunk_size=1024, # Each chunk is of size 1024\n",
-    "    chunk_overlap=128 # Neigboring chunks overlap by 128 characters\n",
+    "    chunk_size=1024*4, # Each chunk is of size 1024\n",
+    "    chunk_overlap=128*2 # Neigboring chunks overlap by 128 characters\n",
     ") \n",
     "\n",
     "texts = text_splitter.split_documents(document)"
diff --git a/5. Prompt Engineering.ipynb b/5. Prompt Engineering.ipynb
index 3921e7f..580e7bb 100644
--- a/5. Prompt Engineering.ipynb	
+++ b/5. Prompt Engineering.ipynb	
@@ -98,7 +98,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "plt.style.use('./d4sci.mplstyle')"
+    "plt.style.use('d4sci.mplstyle')"
    ]
   },
   {