diff -r b334cb9383ac -r e8d2f9e0118b text/intro.tex
--- a/text/intro.tex	Fri Nov 18 13:17:36 2011 -0800
+++ b/text/intro.tex	Fri Nov 18 14:24:17 2011 -0800
@@ -542,7 +542,7 @@
 the tongue as well as ``disk-like''.)
 
 Another thing we need a name for is the ability to rotate morphisms around in various ways.
-For 2-categories, ``strict pivotal" is a standard term for what we mean.
+For 2-categories, ``strict pivotal" is a standard term for what we mean. (See \cite{MR1686423, 0908.3347}, although note there the definition is only for monoidal categories; one can think of a monoidal category as a 2-category with only one $0$-morphism, then relax this requirement, to obtain the sensible notion of pivotal (or strict pivotal) for 2-categories. Compare also \cite{1009.0186} which addresses this issue explicitly.)
 A more general term is ``duality", but duality comes in various flavors and degrees.
 We are mainly interested in a very strong version of duality, where the available ways of
 rotating $k$-morphisms correspond to all the ways of rotating $k$-balls.