Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thu sach » thuat sach, thuoc sach, thu hoach
hanh tai » thanh tai, hang tai, han tai
tai cua » thai cua, tai cuc, tri cua
va hanh » van hanh, va thanh, va danh
cac dac » cac dan, cac dai, cac bac
tu sach » su sach, te sach, tu cach
hieu va » lieu va
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
dac va » duc va, day va, dat va

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