Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thu sach » thuat sach, thuoc sach, thu hoach
luat tuc » luat thue
van luat » va luat, van xuat, dan luat
hanh di » hanh de, hang di, danh di
tu sach » su sach, te sach, tu cach
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) ky nang ma hoi. hieu van luat tuc va ((hanh di) OR (hanh vi)) cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang ma hoi. hieu van luat tuc va ((hanh di) OR (hanh vi)) cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky nang ma hoi. hieu van luat tuc va ((hanh di) OR (hanh vi)) cua vat".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang ma hoi. hieu van luat tuc va ((hanh di) OR (hanh vi)) cua vat*.