Perhaps you should try some spelling variations:
dai truc » dai thuc, doan truc, dai trung
tu sach » thu sach, su sach, te sach
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
tu tren » tu truyen, tu tieng, tu trong
hieu va » lieu va, hieu qua
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
va dai » va dao, vi dai, va dau
vi tu » vi tut, voi tu, va tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((ty nang) or (ty hang)) xa hoi. hieu va dai truc ((va hanh) OR (va danh)) vi tu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty hang)) xa hoi. hieu va dai truc ((va hanh) OR (va danh)) vi tu tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) or (ty hang)) xa hoi. hieu va dai truc ((va hanh) OR (va danh)) vi tu tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ty hang)) xa hoi. hieu va dai truc ((va hanh) OR (va danh)) vi tu tren*.