onto-debugger.md

@@ -37,7 +37,7 @@ Select ```File->Open from URL... ``` ,enter the URL http://protege.stanford.edu/
 The process of formulating queries and finding the faulty axioms the Ontology Debugger requires the usage of a reasoner.
 You have to select a reasoner such as HermiT, Pellet, FaCT++ or ELK to be able to start a debugging session. For our tutorial let us choose the already installed *Hermit Reasoner* in the ```Reasoner``` menu. ![reasoner](/uploads/654ee6fdd1959cc9f947945776142d1b/reasoner.PNG)*The Ontology Debugger requires a reasoner. For our tutorial we choose HermiT.*
 
-Please note that reasoners use different techniques to reason over ontologies. Therefore one reasoner may perform better than others on a specific ontology and worse on another ontology.
+Please note that reasoners use different techniques to reason over ontologies. Therefore one reasoner may perform better than others on a specific ontology and worse on another ontology. Sometimes it might be helpful to select a different reasoner if the debugging is too time consuming [1].
 
 ### Step 3: Open the Ontology Debugger Tab
 
@@ -256,3 +256,4 @@ These default preferences were used for this tutorial.
 **enrich and optimize query**: _yes_
 
 
+[1]: http://www.cs.man.ac.uk/~sazonauv/SazonauThesis.pdf
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