Perhaps you should try some spelling variations:
luat thuc » luat thue, luat tuc, luan thuc
dau tren » dau tien, dat tren, dau tieng
cau tren » cu tren, ca tren, cau treo
tinh doi » trinh doc, trinh do, tinh hoc
hieu cua » hieu qua, dieu cua, bieu cua
cua luat » quy luat
sang ma » tang ma, sang tao, mang may
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
va tinh » may tinh
nang ma » tang ma, nang cao, mang may
te sach » toc sach

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 ((nang ma) or (sang ma)) hoi. hieu cua luat thuc va tinh doi ((cau tren) OR (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang ma) OR (sang ma)) hoi. hieu cua luat thuc va tinh doi ((cau tren) OR (dau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang ma) or (sang ma)) hoi. hieu cua luat thuc va tinh doi ((cau tren) OR (dau tren))".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang ma) or (sang ma)) hoi. hieu cua luat thuc va tinh doi ((cau tren) OR (dau tren))*.