diff --git a/README.md b/README.md
index cc33d4b..a7d462a 100644
--- a/README.md
+++ b/README.md
@@ -29,7 +29,7 @@ devtools::install_github("biostatio/ZIM")
 
 ## References
 
-- Yang, M., Zamba, G. K. D., & Cavanaugh, J. E. (2013). Markov regression models for count time series with excess zeros: A partial likelihood approach. Statistical Methodology, 14, 26–38.  <[doi:10.1016/j.stamet.2013.02.001](https://doi.org/10.1016/j.stamet.2013.02.001)> 
+- M Yang, GKD Zamba, JE Cavanaugh. Markov regression models for count time series with excess zeros: A partial likelihood approach. Statistical Methodology, 2013, 14:26–38.  <[doi:10.1016/j.stamet.2013.02.001](https://doi.org/10.1016/j.stamet.2013.02.001)> 
 
-- Yang, M., Cavanaugh, J. E., & Zamba, G. K. (2014). State-space models for count time series with excess zeros. Statistical Modelling: An International Journal, 15(1), 70–90. <[doi:10.1177/1471082X14535530](https://doi.org/10.1177/1471082X14535530)>
+- M Yang, JE Cavanaugh, GKD Zamba. State-space models for count time series with excess zeros. Statistical Modelling, 2015, 15(1):70–90. <[doi:10.1177/1471082X14535530](https://doi.org/10.1177/1471082X14535530)>