Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
tu cach » tu cac
nang ma » tang ma, sang ma, nang cao
hieu he » hieu ve, hiem he, hieu le
ha dung » hai dung, kha dung, nha dung
dat cua » day cua, mat cua, dan cua
ma hoi » mai hoi, xa hoi, ma hoa
he nam » ha nam, nghe nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cach) or (thu sach)) ky nang ma hoi. hieu he nam thu ha dung ((dat cua) OR (dai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (thu sach)) ky nang ma hoi. hieu he nam thu ha dung ((dat cua) OR (dai cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (thu sach)) ky nang ma hoi. hieu he nam thu ha dung ((dat cua) OR (dai cua)) triet".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (thu sach)) ky nang ma hoi. hieu he nam thu ha dung ((dat cua) OR (dai cua)) triet*.