note temporary reference in readme

Author: dcnieho

README.md

@@ -1,9 +1,17 @@
 # GlassesValidator
 Tool for automatic determination of data quality (accuracy and precision) of wearable eye tracker recordings.
 
-Please cite:
-Niehorster, D.C., Hessels, R.S., Benjamins, J.S., Nyström, M. and Hooge, I.T.C. (in preparation).
-GlassesValidator: A data quality tool for eye tracking glasses.
+Please note that this software is currently in beta, and the accompanying paper is not yet published. As such,
+the software is potentially subject to change, and we urge users to carefully check the results generated by
+glassesValidator. Please provide us with feedback on *anything* you notice, *no matter how small*.
+
+A preliminary reference to the upcoming paper is:<br>
+Niehorster, D.C., Hessels, R.S., Benjamins, J.S., Nyström, M. and Hooge, I.T.C. (in preparation). GlassesValidator:
+A data quality tool for eye tracking glasses.
+ 
+However, as long as the paper is not accepted, please cite this work as follows:<br>
+Niehorster, D.C., Hessels, R.S., Benjamins, J.S., Nyström, M. and Hooge, I.T.C. (2022). GlassesValidator:
+A data quality tool for eye tracking glasses. Available from https://github.com/dcnieho/glassesValidator
 
 # How to acquire
 The glassesValidator is available from `https://github.com/dcnieho/glassesValidator`, and supports Windows, MacOS and Linux.