Perhaps you should try some spelling variations:
thien van » thi van
nam thuoc » nam thuc, nam thu, nha thuoc
hieu van » hieu va, lieu va, hieu ve
thuoc va » thuc va, thuoc ma, thuong va
su sach » so sach, vu sach
nang ma » tang ma, sang ma, nang cao
va tinh » may tinh
tinh va » tich va, trinh van, trinh vat
va cua » va chua, via cua, ca cua
cua te » cua tu

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 thieu ((nang ma) or (nang x)) hoi. ((hieu van) OR (thien van)) nam thuoc va tinh va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thieu ((nang ma) OR (nang x)) hoi. ((hieu van) OR (thien van)) nam thuoc va tinh va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thieu ((nang ma) or (nang x)) hoi. ((hieu van) OR (thien van)) nam thuoc va tinh va cua te".
• Adding a wildcard symbol may retrieve word variants: su sach thieu ((nang ma) or (nang x)) hoi. ((hieu van) OR (thien van)) nam thuoc va tinh va cua te*.