Perhaps you should try some spelling variations:
su triet » su viet, ve triet
hanh tai » thanh tai, hang tai, han tai
ban hanh » ban hang
thu san » thuy san, thu ban, phu san
soc ban » hoc ban, coc ban, so ban
vu cham » va cham, vu kham, tu cham
nang ma » tang ma, sang ma, nang cao
hieu vu » hieu va, hieu ve, hieu su
su tien » su kien, su hien, tu tieng
san ky » sang ky, van ky, dan ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu san ky ((nang ma) or (nang x)) hoi. hieu vu cham soc ban hanh tai ((su triet) OR (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu san ky ((nang ma) OR (nang x)) hoi. hieu vu cham soc ban hanh tai ((su triet) OR (su tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu san ky ((nang ma) or (nang x)) hoi. hieu vu cham soc ban hanh tai ((su triet) OR (su tien))".
• Adding a wildcard symbol may retrieve word variants: thu san ky ((nang ma) or (nang x)) hoi. hieu vu cham soc ban hanh tai ((su triet) OR (su tien))*.