Update README.md

README.md

@@ -8,7 +8,7 @@ EMAN2 (blake.bcm.edu/emanwiki/EMAN2), used to compute the FSC.
 
 gnuplot (www.gnuplot.info/)
 
-## instalation
+## installation
 
 1. clone the repository or download the zip and extract it (we refer to the root of the source tree as `SRC_DIR`).
 2. compile gmconvert: `cd ${SRC_DIR}/gmconvert/src ; make ; cd -`
@@ -50,4 +50,8 @@ Kawabata, T. , Biophys J 2008 Nov 15;95(10):4643-58.
 
 http://www.cell.com/biophysj/fulltext/S0006-3495%2808%2978604-1
 
+[3] EMAN2: an extensible image processing suite for electron microscopy. 
 
+G. Tang, L. Peng, P.R. Baldwin, D.S. Mann, W. Jiang, I. Rees & S.J. Ludtke. 
+
+(2007) J Struct Biol. 157, 38-46. PMID: 16859925 
\ No newline at end of file