diff --git a/semester4/dmdb/data-modelling-databases-summary.pdf b/semester4/dmdb/data-modelling-databases-summary.pdf
index 4f69c20..a2717c7 100644
Binary files a/semester4/dmdb/data-modelling-databases-summary.pdf and b/semester4/dmdb/data-modelling-databases-summary.pdf differ
diff --git a/semester4/dmdb/parts/02_theory-background/01_normal-forms/00_intro.tex b/semester4/dmdb/parts/02_theory-background/01_normal-forms/00_intro.tex
new file mode 100644
index 0000000..8ca9f0a
--- /dev/null
+++ b/semester4/dmdb/parts/02_theory-background/01_normal-forms/00_intro.tex
@@ -0,0 +1,10 @@
+\newpage
+\subsection{Normal Forms}
+\inlinedefinition[Normal forms] describe the properties of concrete schemas based on functional dependencies in terms of data redundancy and data integrity.
+
+For each of the normal forms, we need to be able to decide:
+\begin{itemize}
+    \item whether $\{ R, F \}$ satisfies the NF
+    \item given $\{ R, F \}$ that satisfies the NF, what are the properties?
+    \item how can we generate new schema $R'$, such that $\{ R', F \}$ satisfies the given normal form
+\end{itemize}
diff --git a/semester4/dmdb/parts/02_theory-background/01_normal-forms/01_first-nf.tex b/semester4/dmdb/parts/02_theory-background/01_normal-forms/01_first-nf.tex
new file mode 100644
index 0000000..02bb338
--- /dev/null
+++ b/semester4/dmdb/parts/02_theory-background/01_normal-forms/01_first-nf.tex
@@ -0,0 +1 @@
+\subsubsection{First Normal Form}
diff --git a/semester4/dmdb/parts/02_theory-background/01_normal-forms/02_second-nf.tex b/semester4/dmdb/parts/02_theory-background/01_normal-forms/02_second-nf.tex
new file mode 100644
index 0000000..e69de29
diff --git a/semester4/dmdb/parts/02_theory-background/01_normal-forms/03_third-nf.tex b/semester4/dmdb/parts/02_theory-background/01_normal-forms/03_third-nf.tex
new file mode 100644
index 0000000..e69de29
diff --git a/semester4/dmdb/parts/02_theory-background/01_normal-forms/04_bncf.tex b/semester4/dmdb/parts/02_theory-background/01_normal-forms/04_bncf.tex
new file mode 100644
index 0000000..e69de29
diff --git a/semester4/dmdb/parts/02_theory-background/main.tex b/semester4/dmdb/parts/02_theory-background/main.tex
index d42b2ed..e294049 100644
--- a/semester4/dmdb/parts/02_theory-background/main.tex
+++ b/semester4/dmdb/parts/02_theory-background/main.tex
@@ -9,4 +9,11 @@
 \input{parts/02_theory-background/00_functional-dependencies/05_using.tex}
 % \input{parts/02_theory-background/00_functional-dependencies/}
 
+\input{parts/02_theory-background/01_normal-forms/00_intro.tex}
+\input{parts/02_theory-background/01_normal-forms/01_first-nf.tex}
+\input{parts/02_theory-background/01_normal-forms/02_second-nf.tex}
+\input{parts/02_theory-background/01_normal-forms/03_third-nf.tex}
+\input{parts/02_theory-background/01_normal-forms/04_bncf.tex}
+% \input{parts/02_theory-background/01_normal-forms/}
+
 % \input{parts/02_theory-background/}