Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
van bac » van ban, van bao, van hac
truc va » thuc va, thuc vat, trung va
va danh » va dinh, va dan, va hanh
danh de » hanh de, dan de, dang de
cua tre » cuu tre, cua triet, dua tren
van ha » van hoa, van chat, van hanh
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 hoa. hieu ((van bac) or (van ha)) truc va danh de ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoa. hieu ((van bac) OR (van ha)) truc va danh de ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ma hoa. hieu ((van bac) or (van ha)) truc va danh de ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ma hoa. hieu ((van bac) or (van ha)) truc va danh de ((cua tre) OR (cua te))*.