Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
va triet » va trien, ve triet, cua triet
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
truc va » thuc va, thuc vat, trung va
van tai » von tai, van tuan
va cau » van cau, va cac, va dau
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (hoc sach)) ky lang xa hoi. lieu va cau truc va van tai ((va triet) OR (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (hoc sach)) ky lang xa hoi. lieu va cau truc va van tai ((va triet) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (hoc sach)) ky lang xa hoi. lieu va cau truc va van tai ((va triet) OR (va thiet))".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (hoc sach)) ky lang xa hoi. lieu va cau truc va van tai ((va triet) OR (va thiet))*.