Perhaps you should try some spelling variations:
dan thiet » luan thiet, toan thiet, doan thien
va tinh » may tinh
va hanh » van hanh, va thanh, va danh
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
nang ma » tang ma, sang ma, nang cao
sac ky » cac ky, sai ky
vi dan » voi dan, vi dai, va dan
tu sac » tu sach, tu cac, tu san

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 ((mang may) or (nang ma)) hoi. hieu ve cham soc ((va hanh) or (va tinh)) vi dan thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky ((mang may) OR (nang ma)) hoi. hieu ve cham soc ((va hanh) OR (va tinh)) vi dan thiet.
• Adding a wildcard symbol may retrieve word variants: tu sac ky ((mang may) or (nang ma)) hoi. hieu ve cham soc ((va hanh) or (va tinh)) vi dan thiet*.