code: def get_sources_by_member(base_url=BASE_URL_API, limit=LIMIT_DEFAULT):
      
      url = '{}sources-by-member/'.format(base_url)
      page = '{}?{}'.format(url, urlencode({'limit': limit}))
      results = []
      while True:
          data = get_page(page)
          results = results + data['results']
          if data['next']:
              page = data['next']
          else:
              break
      return results
docs: Function returns which activities each member has joined.
  
      :param base_url: It is URL: `https://www.openhumans.org/api/public-data`.
      :param limit: It is the limit of data send by one request.