Perhaps you should try some spelling variations:
thieu nhanh » thien thanh, hien nhanh, hieu nganh
nhanh cau » nhanh cay, thanh chau, nhanh ha
nam thuc » nam thuoc, am thuc, nam thu
thuc van » thuc vat, thuc dan, thuc va
hanh tai » thanh tai, hang tai, han tai
nhan tai » hang tai, van tai, toan tai
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
qua nam » quan nam, cua nam, quang nam

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 thieu nhanh cau hoi. hieu qua nam thuc van ((hanh tai) or (nhan tai)) su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thieu nhanh cau hoi. hieu qua nam thuc van ((hanh tai) OR (nhan tai)) su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach thieu nhanh cau hoi. hieu qua nam thuc van ((hanh tai) or (nhan tai)) su triet*.