Perhaps you should try some spelling variations:
nang thai » nang tai, dang thai, lang thai
su triet » su viet, su tien, ve triet
cam thue » cam thu, lam thue, nam thue
ty nang » ky nang, ty hang, ly nang
hieu va » lieu va, hieu qua
su sach » so sach, vu sach
thue va » thuc va, thuyet va, thuc vat
va nang » van nang, da nang, cam nang
thai su » thai xu, tai su, thap su
tu sach » thu sach, te sach, tu cach
va cam » va cham, va cac, va cao

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) or (su sach)) ((ty nang) OR (ty xang)) xa hoi. hieu va cam thue va nang thai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ((ty nang) OR (ty xang)) xa hoi. hieu va cam thue va nang thai su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ((ty nang) OR (ty xang)) xa hoi. hieu va cam thue va nang thai su triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ((ty nang) OR (ty xang)) xa hoi. hieu va cam thue va nang thai su triet*.