diff --git a/NAMESPACE b/NAMESPACE
index 2630f3f..808c243 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -299,6 +299,7 @@ export(prep.alsbasecorr)
 export(prep.autoscale)
 export(prep.msc)
 export(prep.norm)
+export(prep.ref2km)
 export(prep.savgol)
 export(prep.snv)
 export(prepCalData)
diff --git a/NEWS.md b/NEWS.md
index 88a1c2a..ec834ba 100755
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,11 +1,15 @@
 v.0.11.3
 ========
 
+* added [Procrustes Cross-Validation method](https://doi.org/10.1021/acs.analchem.0c02175), `pcv()` (it is also available as a [separate project](https://github.com/svkucheryavski/pcv)).
+
+* added Kubelka-Munk transformation for diffuse reflectance spectra (`prep.ref2km()`).
+
 * fixed bug [#94](https://github.com/svkucheryavski/mdatools/issues/94) which caused wrong limits in PCA distance plot when outliers are present but excluded.
 
 * fixed bug [#95](https://github.com/svkucheryavski/mdatools/issues/95) which lead to issues when PLS regression methods (e.g. `plotRMSE()`) are used for PLS-DA model object.
 
-* added [Procrustes Cross-Validation method](https://doi.org/10.1021/acs.analchem.0c02175), `pcv()` (it is also available as a [separate project](https://github.com/svkucheryavski/pcv)).
+* added additional check that parameter `cgroup` for plotting functions is provided as a vector or as a factor to avoid confusion.
 
 * added link to [YouTube channel](https://www.youtube.com/channel/UCox0H4utfMq4FIu2kymuyTA) with Chemometric course based on *mdatools* package.
 
diff --git a/README.md b/README.md
index 30ff7ec..2df171f 100755
--- a/README.md
+++ b/README.md
@@ -1,5 +1,6 @@
 Multivariate Data Analysis Tools
 ===========================================
+![GitHub build status](https://github.com/actions/mdatools/workflows/R-CMD-check/badge.svg)
 ![Travis (build status)](https://img.shields.io/travis/svkucheryavski/mdatools?color=blue&style=flat-square "Travis CI build status")
 ![Downloads (CRAN)](https://cranlogs.r-pkg.org/badges/grand-total/mdatools?color=blue&logo=R&style=flat-square "Downloads from CRAN")
 ![GitHub All Releases](https://img.shields.io/github/downloads/svkucheryavski/mdatools/total?color=blue&logo=Github&style=flat-square "Downloads from GitHub")