diff --git a/luku07.tex b/luku07.tex
index ac14546..13de7b0 100644
--- a/luku07.tex
+++ b/luku07.tex
@@ -983,7 +983,9 @@ $2^m$ distinct rows and the time complexity is
 $O(n 2^{2m})$.
 
 As a final note, there is also a surprising direct formula
-for calculating the number of tilings \cite{kas61,tem61}:
+for calculating the number of tilings\footnote{Surprisingly,
+this formula was discovered independently
+by \cite{kas61} and \cite{tem61} in 1961.}:
 \[ \prod_{a=1}^{\lceil n/2 \rceil} \prod_{b=1}^{\lceil m/2 \rceil} 4 \cdot (\cos^2 \frac{\pi a}{n + 1} + \cos^2 \frac{\pi b}{m+1})\]
 This formula is very efficient, because it calculates
 the number of tilings in $O(nm)$ time,
diff --git a/luku20.tex b/luku20.tex
index 28c8fbb..1e7a8d0 100644
--- a/luku20.tex
+++ b/luku20.tex
@@ -431,8 +431,6 @@ by using one of the following techniques:
 \index{Edmonds–Karp algorithm}
 
 The \key{Edmonds–Karp algorithm} \cite{edm72}
-is a variant of the
-Ford–Fulkerson algorithm that
 chooses each path so that the number of edges
 on the path is as small as possible.
 This can be done by using breadth-first search
@@ -443,7 +441,7 @@ of the algorithm is $O(m^2 n)$.
 
 \index{scaling algorithm}
 
-The \key{scaling algorithm} uses depth-first
+The \key{scaling algorithm} \cite{ahu91} uses depth-first
 search to find paths where each edge weight is
 at least a threshold value.
 Initially, the threshold value is