Perhaps you should try some spelling variations:
trinh vat » trinh van, trinh luat, sinh vat
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
vat cua » mat cua, bat cua, dat cua
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
hieu ve » hieu van
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
tuc va » truc va, tuc xa, duc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang xa hoi. ((hieu ve) or (hieu va)) coc ((tuc va) OR (thuc va)) trinh vat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang xa hoi. ((hieu ve) OR (hieu va)) coc ((tuc va) OR (thuc va)) trinh vat cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang xa hoi. ((hieu ve) or (hieu va)) coc ((tuc va) OR (thuc va)) trinh vat cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang xa hoi. ((hieu ve) or (hieu va)) coc ((tuc va) OR (thuc va)) trinh vat cua tre*.