diff --git a/thesis.bib b/thesis.bib
index b234f12..023be96 100644
--- a/thesis.bib
+++ b/thesis.bib
@@ -1413,6 +1413,13 @@
   year      = {2010}
 }
 
+@book{Dybvig03,
+  author    = {R. Kent Dybvig},
+  title     = {The {Scheme} Programming Language, Third Edition},
+  publisher = {{MIT} Press},
+  year      = {2003}
+}
+
 # Haskell
 @misc{JonesABBBFHHHHJJLMPRRW99,
   author = {Simon Peyton Jones
@@ -3267,3 +3274,58 @@
   pages     = {1--32},
   year      = {2003}
 }
+
+# Undelimited control is insufficient to express mutable state
+@techreport{FriedmanS00,
+  author = {Daniel P. Friedman and Amr Sabry},
+  title = {Recursion is a Computational Effect},
+  institution = {Computer Science Department, Indiana University},
+  address   = {Bloomington, Indiana 47405, USA},
+  type = {Technical report},
+  number = {546},
+  year = {200},
+}
+
+# Fortran
+@inproceedings{BackusBBGHHNSSS57,
+  author    = {John W. Backus and
+               Robert J. Beeber and
+               Sheldon Best and
+               Richard Goldberg and
+               Lois M. Haibt and
+               Harlan L. Herrick and
+               Robert A. Nelson and
+               David Sayre and
+               Peter B. Sheridan and
+               H. Stern and
+               Irving Ziller and
+               Robert A. Hughes and
+               R. Nutt},
+  title     = {The {FORTRAN} automatic coding system},
+  booktitle = {{IRE-AIEE-ACM} Computer Conference (Western)},
+  pages     = {188--198},
+  publisher = {{ACM}},
+  year      = {1957}
+}
+
+# Algol
+@article{BackusBGKMPRSVWWW60,
+  author    = {John W. Backus and
+               Friedrich L. Bauer and
+               Julien Green and
+               C. Katz and
+               John McCarthy and
+               Alan J. Perlis and
+               Heinz Rutishauser and
+               Klaus Samelson and
+               Bernard Vauquois and
+               Joseph Henry Wegstein and
+               Adriaan van Wijngaarden and
+               Michael Woodger},
+  title     = {Report on the algorithmic language {ALGOL} 60},
+  journal   = {Commun. {ACM}},
+  volume    = {3},
+  number    = {5},
+  pages     = {299--314},
+  year      = {1960}
+}
diff --git a/thesis.tex b/thesis.tex
index 0b9fe68..72df048 100644
--- a/thesis.tex
+++ b/thesis.tex
@@ -435,14 +435,45 @@ effectful programming through the lens of a singular effect, namely,
 global mutable state.
 
 \subsection{Early days of direct-style}
-
-It is well-known that $\Callcc$ exhibits both time and space
-performance problems for various implementing various
-effects~\cite{Kiselyov12}.
+%
+Programming in its infancy was effectful as the idea of first-class
+control was conceived already during the design of the programming
+language Algol~\cite{BackusBGKMPRSVWWW60} -- one of the early
+high-level programming languages along with
+Fortran~\cite{BackusBBGHHNSSS57} and Lisp~\cite{McCarthy60} -- when
+\citet{Landin98} sought to model unrestricted goto-style jumps using
+an extended $\lambda$-calculus. The nature of \citeauthor{Landin98}'s
+control facility is undelimited; its power was recognised early by
+\citet{Burstall69}, who used it to implement a thread scheduler.
+%
+\citeauthor{Landin98}'s control facility did not gain popularity as a
+practical programming abstraction~\cite{Felleisen87b}.
+
+%
+% The power of \citeauthor{Landin98}'s control facility was recognised early The nature of the first-class control introduced by
+% \citeauthor{Landin98} was undelimited. However, 
+
+% The early high-level programming languages
+% Fortran~\cite{BackusBBGHHNSSS57}, Algol~\cite{BackusBGKMPRSVWWW60},
+% and Lisp~\cite{McCarthy60} all hard-wire a particular set of effects
+% into their semantics. The usage of effects in these languages is
+% completely untracked, although, the languages belonging to the Lisp
+% family have adopted a naming convention to suffix names of
+% side-effecting operations with exclamation points, e.g. the state
+% modification operation is named $\keyw{set!}$~\cite{Dybvig03}.
+
+% The idea of undelimited first-class control was conceived during the
+% development of Algol~\cite{Landin65,Landin65a,Landin98}. The probably
+% most famous form of undelimited control, $\Callcc$, appeared
+% later~\cite{AbelsonHAKBOBPCRFRHSHW85}.
+
+% It is well-known that $\Callcc$ exhibits both time and space
+% performance problems for various implementing various
+% effects~\cite{Kiselyov12}.
 %
 \subsubsection{Builtin mutable state}
 It is common to find mutable state builtin into the semantics of
-mainstream programming language. However, different languages vary in
+mainstream programming languages. However, different languages vary in
 their approach to mutable state. For instance, state mutation
 underpins the foundations of imperative programming languages
 belonging to the C family of languages. They do typically not