My sister and her family are canadian citizens. my dad applied in 2013 thier application was rejected stating financial condition. then we applied in dec 2017 visa got rejected stating "OTHER REASONS" " your proposed travel is not reasonable in light of one more of , your employment history, level of establishment, travel history, and your travel plans. and Jan 2018 again it is rejected : OTHER REASONS. we are really sad, my parents has good track record of travel history, every year he keeps travelling. and his dream is to see canada and his daughter whom he has not seen from last 4 years. we had mentioned that they are going to stay only one month. can some one can give me suggestion to apply once agian so has to what points i need to consider and what additional documents we have to keep it. any tips and suggestions welcome.