Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
hieu va » lieu va, hieu qua
cac luc » cau luc, coc luc, cac nuoc
dao dai » dat dai, tao dai, do dai
dao dan » dao van, cao dang, dao dong
cuu tre » cua tre, cau tren, cau treo
luc ca » luc cao, luc cua, luc va
x hoi » xa hoi, o hoi, x ho

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)) ky nang x hoi. hieu va cac luc ca ((dao dai) OR (dao dan)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang x hoi. hieu va cac luc ca ((dao dai) OR (dao dan)) cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky nang x hoi. hieu va cac luc ca ((dao dai) OR (dao dan)) cuu tre*".