Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
vanh tai » van tai, hanh tai, anh tai
cham tuc » nham thuc, tham thuc, cham soc
tai cua » thai cua, tai cuc, tri cua
va vanh » va van, va danh, va hanh
hoc hoi » hoc khoi, hoc hoa, hoc noi
hieu va » lieu va, hieu qua
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
ho hoi » hoa hoi, hoi hoi, co hoi
cua te » cua tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky nang ((ho hoi) or (hoc hoi)). hieu va ((cham tuc) OR (pham thuc)) va vanh tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang ((ho hoi) OR (hoc hoi)). hieu va ((cham tuc) OR (pham thuc)) va vanh tai cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang ((ho hoi) or (hoc hoi)). hieu va ((cham tuc) OR (pham thuc)) va vanh tai cua te*".