Perhaps you should try some spelling variations:
voi doanh » von doanh, hoa doanh, van doanh
phat xuc » chat xuc, phat xuat, phap xu
tu sach » thu sach, su sach, tu cach
te sach » toc sach
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
cua cua » cua chua, ca cua, qua cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang

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 (te sach)) y nang ma hoa. hieu va phat xuc ((voi doanh) OR (tri doanh)) cua cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) y nang ma hoa. hieu va phat xuc ((voi doanh) OR (tri doanh)) cua cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) y nang ma hoa. hieu va phat xuc ((voi doanh) OR (tri doanh)) cua cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) y nang ma hoa. hieu va phat xuc ((voi doanh) OR (tri doanh)) cua cua tre*.