diff --git a/quapy/CHANGE_LOG.txt b/quapy/CHANGE_LOG.txt
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@@ -1,6 +1,9 @@
 Change Log 0.1.8
 ----------------
 
+- Fixed ThresholdOptimization methods (X, T50, MAX, MS and MS2). Thanks to Tobias Schumacher and colleagues for pointing
+    this out in Appendix A of "Schumacher, T., Strohmaier, M., & Lemmerich, F. (2021). A comparative evaluation of 
+    quantification methods. arXiv:2103.03223v3 [cs.LG]"
 - Added HDx and DistributionMatchingX to non-aggregative quantifiers (see also the new example "comparing_HDy_HDx.py")
 - New UCI multiclass datasets added (thanks to Pablo González). The 5 UCI multiclass datasets are those corresponding
     to the following criteria: