Perhaps you should try some spelling variations:
sach tien » sach tren, sach thieu
sach truc » cach thuc, sach tren, sach thu
thuy dinh » thuy linh, thuy tinh, thuy binh
dinh khoa » sinh khoa, doanh khoa, trinh khoa
phu thong » phap thong, khau thong, phan thong
pho thong » he thong
sach bai » sach dao, cac bai, sach xa

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 bai) or (((sach truc) or (sach tien)))) thuy dinh khoa ((phu thong) OR (pho thong))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach bai) OR (((sach truc) OR (sach tien)))) thuy dinh khoa ((phu thong) OR (pho thong)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach bai) or (((sach truc) or (sach tien)))) thuy dinh khoa ((phu thong) OR (pho thong))".
• Adding a wildcard symbol may retrieve word variants: su ((sach bai) or (((sach truc) or (sach tien)))) thuy dinh khoa ((phu thong) OR (pho thong))*.