Perhaps you should try some spelling variations:
nhan loai » phan loai, nhan tai
thanh cau » thanh chau, thanh mau, nhanh cau
sach thi » sach thu, sach tai, sach thieu
nam thuc » nam thuoc, am thuc, nam thu
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
qua nam » quan nam, cua nam, quang nam
thuc va » thuc vat, thuc dan, thuc day
han tai » hang tai, nhan tai, van tai

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

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