====== Loki Reference links ======
  * [[http://lhcb-release-area.web.cern.ch/LHCb-release-area/DOC/davinci/latest_doxygen/d7/dae/namespace_lo_ki_1_1_cuts.html | Loki Namespace]] (most up to date)
  * [[https://twiki.cern.ch/twiki/bin/view/LHCb/LoKiHybridFilters#Particle_Functors | Recommended LoKi::Hybrid Functors]] (most accessible)
  * [[https://twiki.cern.ch/twiki/bin/view/LHCb/LoKiParticleFunctions | LoKi's Particle Functions]]