1. Your paper:
   A smoke-free environment brings economical benefits to the hospitality industry as a whole. According to
   [Christophi, Paisi, Pampaka, Kehagias, Vardavas and Connolly (2013) / Christophi et al (2013)], upon implementation of smoke-free policy in hospitality venues, the gross income of hospitality industry increases.
   ANS
   A smoke-free environment brings economical benefits to the hospitality industry as a whole. According to [Christophi, Paisi, Pampaka, Kehagias, Vardavas and Connolly / Christophi et al], upon implementation of smoke-free policy in hospitality venues, the gross income of hospitality industry increases. (34)