Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
sach ky » sach y, sach ty, sach kem
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
su tien » su kien, su hien, tu tieng
sac ky » cac ky, sai ky
va cam » va cham, va cac, va cao
cam tu » cam thu, nam tu, dam tu
ki su » ky su

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: vu ((sach ky) OR (sac ky)) nang x ho. hieu va cam tu ((va thanh) or (va danh)) ki su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu ((sach ky) OR (sac ky)) nang x ho. hieu va cam tu ((va thanh) OR (va danh)) ki su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu ((sach ky) OR (sac ky)) nang x ho. hieu va cam tu ((va thanh) or (va danh)) ki su tien".
• Adding a wildcard symbol may retrieve word variants: vu ((sach ky) OR (sac ky)) nang x ho. hieu va cam tu ((va thanh) or (va danh)) ki su tien*.