Perhaps you should try some spelling variations:
nam truc » nam truoc, nam trung, nam thuoc
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
su sach » so sach, vu sach
le lang » le tang, le dang, le xang
ly lang » ly hang, ly vang, ly lanh
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu

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 ((ly lang) or (le lang)) xa hoi. hieu van ((nam truc) OR (nam thuc)) va danh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ly lang) OR (le lang)) xa hoi. hieu van ((nam truc) OR (nam thuc)) va danh vi cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ly lang) or (le lang)) xa hoi. hieu van ((nam truc) OR (nam thuc)) va danh vi cuu tre*".