Perhaps you should try some spelling variations:
lam duoc » nam duoc, luat duoc, lam thuoc
hanh tri » thanh tri, hanh tai, hanh trinh
sach doi » sach hoi, sach moi, sach dao
hieu van » hieu va, thien van, lieu va
tri cuu » tri cua, tra cuu, trinh cuu
va hanh » van hanh, va thanh, va danh
lam xuc » cam xuc
sach ty » sach y, sach tu, sach thu
hang xa » hoang xa, hang va, hang ca
cuu tre » cua tre, cau tren, cau treo

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 ty) or (sach doi)) hang xa hoi. hieu van ((lam xuc) OR (lam duoc)) va hanh tri cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach doi)) hang xa hoi. hieu van ((lam xuc) OR (lam duoc)) va hanh tri cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) or (sach doi)) hang xa hoi. hieu van ((lam xuc) OR (lam duoc)) va hanh tri cuu tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach doi)) hang xa hoi. hieu van ((lam xuc) OR (lam duoc)) va hanh tri cuu tre*.