Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
sach thu » sach thue, sach thieu, sach tham
thuoc va » thuc va, thuoc ma, thuong va
su sach » so sach, vu sach
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
va tinh » may tinh
tinh va » tich va, trinh van, trinh vat
cua tre » cua te, cuu tre, cua triet
va nam » van nam, ha nam, va nay
va cua » va chua, via cua, ca cua

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 thu ((nang ma) or (nang x)) hoi. hieu va nam thuoc va tinh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu ((nang ma) OR (nang x)) hoi. hieu va nam thuoc va tinh va cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach thu ((nang ma) or (nang x)) hoi. hieu va nam thuoc va tinh va cua tre*.