PLANET HUNTERS. VI. AN INDEPENDENT CHARACTERIZATION OF KOI-351 AND SEVERAL LONG PERIOD PLANET CANDIDATES FROM THE KEPLER ARCHIVAL DATAThis publication has been made possible through the work of more than 280,000 volunteers in the Planet Hunters project, whose contributions are individually acknowledged at http://www. planethunters. org/authors. The authors especially thank the Planet Hunters volunteers who participated in identifying and analyzing the candidates presented in this paper. They are individually recognized at http://www. planethunters. org/PH6.