Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
va triet » va thiet, va trien, ve triet
sach thi » sach thu, sach tai, sach thieu
thi hang » thi hanh, thi nang, thi hong
hanh tai » thanh tai, hang tai, han tai
va hanh » van hanh, va thanh, va danh
te sach » toc sach
hoc dai » hoc dan
hoc doi » hoc noi, hoc moi, hoc do
hieu le » hieu ve, hieu he, hieu ly
tai va » thai va, mai va, tri va
nuoc » quoc, duoc, ngoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach thi hang ((hoc doi) OR (hoc dai)). hieu le ((nam thuoc) or (nha nuoc)) va hanh tai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach thi hang ((hoc doi) OR (hoc dai)). hieu le ((nam thuoc) OR (nha nuoc)) va hanh tai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach thi hang ((hoc doi) OR (hoc dai)). hieu le ((nam thuoc) or (nha nuoc)) va hanh tai va triet".
• Adding a wildcard symbol may retrieve word variants: te sach thi hang ((hoc doi) OR (hoc dai)). hieu le ((nam thuoc) or (nha nuoc)) va hanh tai va triet*.