revise links and references (#5)

Author: gaelforget

README.md

@@ -11,7 +11,7 @@
 [various grids]: ftp://mit.ecco-group.org/ecco_for_las/version_4/grids/grids_input/
 [gcmfaces_demo.m]: https://github.com/gaelforget/gcmfaces/blob/master/gcmfaces_demo.m
 
-**gcmfaces** is a Matlab toolbox designed to handle results of [MITgcm][] ocean simulations such as [ECCO v4 r2][] and earth variables more generally (Forget et al 2015). It allows users to seamlessly deal with various gridding approaches (e.g., all grids distributed via <ftp://mit.ecco-group.org/ecco_for_las/version_4/grids/grids_input/>) using compact and generic codes as explained in the user guide ([gcmfaces.pdf][]). It includes many basic and more evolved functionalities for plotting global maps, computing transports and budgets, etc. as illustrated by [gcmfaces_demo.m][] and the standard analysis (see Forget et al., 2015, 2016).  
+**gcmfaces** is a Matlab toolbox designed to handle results of [MITgcm][] ocean simulations such as [ECCO v4 r2][] (Forget et al 2016) and earth variables more generally (Forget et al 2015). It allows users to seamlessly deal with various gridding approaches (e.g., all grids distributed via <ftp://mit.ecco-group.org/ecco_for_las/version_4/grids/grids_input/>) using compact and generic codes as explained in the user guide ([gcmfaces.pdf][]). It includes many basic and more evolved functionalities for plotting global maps, computing transports and budgets, etc. as illustrated by [gcmfaces_demo.m][] and the standard analysis (see Forget et al., 2015, 2016).  
 
 Forget, G., J.-M. Campin, P. Heimbach, C. N. Hill, R. M. Ponte, and C. Wunsch, 2015: ECCO version 4: an integrated framework for nonlinear inverse modeling and global ocean state estimation. Geoscientific Model Development, 8 (10), 3071–3104, doi:10.5194/gmd-8-3071-2015, URL <http://www.geosci-model-dev.net/8/3071/2015/>