Classical Topology and Combinatorial Group Theory
J. Stillwell, SpringerVerlag, 1993
 p.21, paragraph 2: the definition of the orientation that
an nsimplex induces on its faces is incorrect.
 p.72, paragraph 2 and Figure 88: the procedure to reduce
the number of vertices equivalent to Q is incorrect.
What is needed is not that Q is inequivalent to P,
but that Q is inequivalent
to the unlabelled vertex incident to edges b and c in Figure 88.
The Knot Book
C. Adams, W.H. Freeman and Co, 1994
 p.98, Exercise 4.19, the formula should read
g = (1+cs)/2.
