What are the research problems Vernier Effect is related to?
SELECT DISTINCT ?problems, ?problems_labels
WHERE {
  ?papers rdf:type orkgc:Paper.
  ?papers rdfs:label ?papers_labels.
  FILTER(REGEX(?papers_labels, "Vernier Effect", "i"))
  ?papers orkgp:P31 ?contrib.
  ?contrib orkgp:P32 ?problems.
  ?problems rdfs:label ?problems_labels.
}