old_contents: import requests, json, urllib
  
  SEARCH_URL = 'http://core.ac.uk:80/api-v2/articles/search/'
  API_KEY = 'FILL THIS IN'
  
  def getCOREMentions(identifier, **kwargs):
      """Return the number of mentions in CORE and a descriptor, as a tuple.
      
      Needs an API key, which can be obtained here: http://core.ac.uk/api-keys/register"""
      params = {
          'apiKey': API_KEY,
          'metadata': 'false',
          'pageSize': 100,
          'page': 1
      }
      params.update(kwargs)
  
      response = requests.get(SEARCH_URL + urllib.quote_plus(identifier), params=params)
      response.raise_for_status()
  
      results = response.json()
  
      return (len(results['data'] or []),
              'mentions in Open Access articles (via http://core.ac.uk/)')
  
new_contents: import requests, json, urllib
  
  SEARCH_URL = 'http://core.kmi.open.ac.uk/api/search/'
  API_KEY = 'FILL THIS IN'
  
  def getCOREMentions(identifier, **kwargs):
      """Return the number of mentions in CORE and a descriptor, as a tuple.
      
      Needs an API key, which can be obtained here: http://core.ac.uk/api-keys/register"""
      params = {
          'api_key': API_KEY,
          'format': 'json',
      }
      params.update(kwargs)
  
      response = requests.get(SEARCH_URL + urllib.quote_plus(identifier), params=params)
      response.raise_for_status()
  
      results = response.json()
      score = results['ListRecords'][0]['total_hits']
  
      return score, 'mentions in Open Access articles (via http://core.ac.uk/)'
  
subject: Switch to using the v1 API to get total hits.