Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
thuc va » thuc vat, thuc dan, thuc day
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
ky tang » ky nang, ky dang, kho tang
ky sang » ky nang, ky dang, duy sang
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
vi cua » vai cua, di cua

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 sang) OR (ky tang)) ma hoi. hieu ve cham ((thuc va) or (tuc xa)) don vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky sang) OR (ky tang)) ma hoi. hieu ve cham ((thuc va) OR (tuc xa)) don vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky sang) OR (ky tang)) ma hoi. hieu ve cham ((thuc va) or (tuc xa)) don vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky sang) OR (ky tang)) ma hoi. hieu ve cham ((thuc va) or (tuc xa)) don vi cua tre*.