Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
dang xay » dang van, van xay
va hanh » van hanh, va thanh, va danh
hieu ve » hieu van
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
xuc va » duc va, tuc va, luc va
vi cau » va cau, ve cau, di cau

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) or (dang xay)) hoi. ((hieu va) or (hieu ve)) cam xuc va hanh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang ma) OR (dang xay)) hoi. ((hieu va) OR (hieu ve)) cam xuc va hanh vi cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang ma) or (dang xay)) hoi. ((hieu va) or (hieu ve)) cam xuc va hanh vi cau tren*.