Perhaps you should try some spelling variations:
hang cao » hoang cao, nang cao, hang cau
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
dan hanh » dang hanh, dan khanh, dan thanh
tu sach » thu sach, su sach, te sach
hang ca » hang va, nang cao, hang tai
qua nam » quan nam, cua nam, quang nam
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y ((hang cao) or (hang ca)) hoi. hieu qua nam thuc dan hanh ((vi cua) or (di cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((hang cao) OR (hang ca)) hoi. hieu qua nam thuc dan hanh ((vi cua) OR (di cua)) triet.
• Adding a wildcard symbol may retrieve word variants: tu sach y ((hang cao) or (hang ca)) hoi. hieu qua nam thuc dan hanh ((vi cua) or (di cua)) triet*.