Perhaps you should try some spelling variations:
vay luan » ly luan, von luan, bai luan
te sach » toc sach
tinh di » tinh doi, trinh di, tinh da
va tinh » may tinh
sach ky » sac ky, sach y, sach ty
va luat » va thuat, cua luat, dan luat
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
cau tre » cau tren, cau treo, cau tra
tuc va » thuc va, truc va, tuc xa
di cau » da cau, diem cau

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