diff --git a/src/bias/MetaD.cpp b/src/bias/MetaD.cpp
index e1e3a7b74f1d8187fef594eac60b8a47be1689aa..5849dab1bc9e8d9226905e195709b4160fee3908 100644
--- a/src/bias/MetaD.cpp
+++ b/src/bias/MetaD.cpp
@@ -74,7 +74,7 @@ utility.
 In the simplest possible implementation of a metadynamics calculation the expense of a metadynamics 
 calculation increases with the length of the simulation as one has to, at every step, evaluate 
 the values of a larger and larger number of Gaussians. To avoid this issue you can
-store the bias on a grid.  This approach is similar to that proposed in \cite babi+08jcp but has the 
+store the bias on a grid.  This approach is similar to that proposed in \cite babi08jcp but has the 
 advantage that the grid spacing is independent on the Gaussian width.
 Notice that you should
 provide either the number of bins for every collective variable (GRID_BIN) or
diff --git a/user-doc/bibliography.bib b/user-doc/bibliography.bib
index 24c7bc46942800596516705444e9ed1a28af4192..96855bf97a0671064cb34fc7a806f54890095bed 100644
--- a/user-doc/bibliography.bib
+++ b/user-doc/bibliography.bib
@@ -1412,7 +1412,7 @@ pages = {1961--1972}
 	Volume = {124},
 	Year = {1961}}
 
-@article{babi+08jcp,
+@article{babi08jcp,
 	Author = {Babin, V. and Roland, C. and Sagui, C.},
 	Journal = {J.~Chem.~Phys.},
 	Pages = {134101},