Fonte positiva dos dados

Sec. de: Green, John. Deixe a neve cair. 2013

http://authorities.loc.gov 4/9/2015: (d.n.)

http://viaf.org/processed/BNF%7C15507109: (d.n.)

http://viaf.org/processed/WKP%7CQ520723: (Maureen Johnson - escritora americana)