Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu van
danh vi » dinh vi, danh di, danh va
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
cam loc » cam lo
loc va » hoc va, luc va
ma hoi » mai hoi, xa hoi, ma hoa
cua te » cua 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 ky nang ma hoi. ((hieu ve) or (hieu va)) cam loc va ((danh vi) OR (hanh vi)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoi. ((hieu ve) OR (hieu va)) cam loc va ((danh vi) OR (hanh vi)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ma hoi. ((hieu ve) or (hieu va)) cam loc va ((danh vi) OR (hanh vi)) cua te".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ma hoi. ((hieu ve) or (hieu va)) cam loc va ((danh vi) OR (hanh vi)) cua te*.