diff --git a/include/crpropa/Source.h b/include/crpropa/Source.h
index e5fdcc765..ad20e4a26 100644
--- a/include/crpropa/Source.h
+++ b/include/crpropa/Source.h
@@ -77,6 +77,20 @@ class SourceList: public SourceInterface {
 	std::string getDescription() const;
 };
 
+/**
+ @class SourceListNumbered
+ @brief List of sources with a fixed number of candidates emitted per source
+
+class SourceListNumbered: public SourceInterface {
+private:
+	std::vector<ref_ptr<Source> > sources; //
+	int nSource; //< number of candidates from each source
+	int alreadyDrawn; //< number of candidates which have already been drawn
+
+public:
+	void add(Source* source); 
+	ref_ptr<Candidate> getCandidate() const;
+};*/
 
 /**
  @class SourceParticleType
@@ -952,6 +966,25 @@ class SourceMassDistribution: public SourceFeature {
 	std::string getDescription();
 };
 
+class SourceStartTime: public SourceFeature {
+private: 
+	double time; //< starting time for the particle 
+
+public: 
+	SourceStartTime(double time);
+	void prepareCandidate(Candidate& cand) const;
+};
+
+class SourceAddProperty: public SourceFeature {
+private: 
+	std::string key; 	//< property key
+	int value; 			//< property 
+
+public: 
+	SourceAddProperty(std::string key, int value);
+	void prepareCandidate(Candidate& cand) const;
+};
+
 /**  @} */ // end of group SourceFeature
 
 } // namespace crpropa
diff --git a/src/Source.cpp b/src/Source.cpp
index 0b9b8a9bb..89b436f54 100644
--- a/src/Source.cpp
+++ b/src/Source.cpp
@@ -1204,4 +1204,20 @@ std::string SourceMassDistribution::getDescription() {
 	return ss.str();
 }
 
+// ----------------------------------------------------------------------------
+
+SourceStartTime::SourceStartTime(double time) : time(time) {}
+
+void SourceStartTime::prepareCandidate(Candidate& cand) const {
+	cand.setTrajectoryLength(time); 
+}
+
+// ----------------------------------------------------------------------------
+
+SourceAddProperty::SourceAddProperty(std::string key, int value) : key(key), value(value) {}
+
+void SourceAddProperty::prepareCandidate(Candidate& cand) const {
+	cand.setProperty(key, value);
+}
+
 } // namespace crpropa