existing design
existing empirical literature
existing evidence
existing gaps
existing guidelines
existing hypotheses
existing information
existing infrastructure
existing institutions
existing interpretations
existing interventions
existing knowledge
existing law
existing levels
existing literature

existing measures
existing mechanisms
existing method
existing methodologies
existing methods
existing model
existing models
existing ones
existing order
existing patterns
existing populations
existing practices
existing problems
existing procedures
existing protocols
existing regulations

existing reports
existing research
existing resources
existing results
existing scales
existing schemes
existing skills
existing solutions
existing sources
existing structures
existing studies
existing system
existing techniques
existing technology
existing tests
existing theories

existing tools
existing treatments
existing vegetation
existing work
exit
exit decisions
exit interviews
exit points
exit polls
exit rates
exit region
exit site
exit tunnel
exo
exocrine cells
exocrine function

exocrine glands
exocrine insufficiency
exocrine pancreas
exocrine pancreatic insufficiency
exocrine pancreatic secretion
exocrine secretion
exocyclic double bond
exocytosis
exocytotic events
exoenzyme activities