Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
trinh van » trinh han, trinh quan, trinh toan
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, dua tren
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
truc va » thuc vat, trung va
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
ve cau » ke cau, va cau, ve cac

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 lang xa hoi. hieu ve cau ((truc va) OR (thuc va)) trinh van ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky lang xa hoi. hieu ve cau ((truc va) OR (thuc va)) trinh van ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky lang xa hoi. hieu ve cau ((truc va) OR (thuc va)) trinh van ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: vu sach ky lang xa hoi. hieu ve cau ((truc va) OR (thuc va)) trinh van ((cua tre) or (cua triet))*.