Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
hanh va » hang va
tu sai » tu bai, tu san, tu cai
sai ky » sac ky
soc va » hoc va, loc va, doc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sai ky ((nang ma) or (nang x)) hoi. hieu ve cham soc va ((hanh va) or (hanh vi)) dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sai ky ((nang ma) OR (nang x)) hoi. hieu ve cham soc va ((hanh va) OR (hanh vi)) dau tren.
• Adding a wildcard symbol may retrieve word variants: tu sai ky ((nang ma) or (nang x)) hoi. hieu ve cham soc va ((hanh va) or (hanh vi)) dau tren*.