Perhaps you should try some spelling variations:
trinh vat » trinh van, trinh luat, sinh vat
hoc thuc » hoc huu
su sach » vu sach
tinh va » tich va, trinh van, tinh gia
thuc va » thuc vat, thuc dan, thuc day
chua te » cua te, chua tu, chua xe
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
so sach » so sanh, bo sach, co sach
va hoc » van hoc

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

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