Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
luat tuc » luat thue
cuu tre » cua tre, cau treo
tinh di » tinh doi, trinh di, tinh da
tuc may » truc may, tu may, tuc xay
sach ky » sach y, sach ty, sach kem
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
va luat » va thuat, vay luan, cua luat
ma hoi » mai hoi, xa hoi, ma hoa
sac ky » cac ky, sai ky

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

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