Perhaps you should try some spelling variations:
day nhanh » day thanh, duy nhanh, dac nhan
sach thue » sach thieu, sach tham, cach thuc
cac thuc » cach thuc, cac thu, can thuc
sach thu » sach thieu, sach tham, cach thuc
day hanh » day thanh, dao hanh, day manh
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac
di cua » dai cua, doi cua, de cua
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu ((sach thu) OR (sach thue)) nang x ho. hieu ve cac thuc ((day hanh) or (day nhanh)) di cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu ((sach thu) OR (sach thue)) nang x ho. hieu ve cac thuc ((day hanh) OR (day nhanh)) di cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu ((sach thu) OR (sach thue)) nang x ho. hieu ve cac thuc ((day hanh) or (day nhanh)) di cua tu".
• Adding a wildcard symbol may retrieve word variants: vu ((sach thu) OR (sach thue)) nang x ho. hieu ve cac thuc ((day hanh) or (day nhanh)) di cua tu*.