Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
dao van » do van, dang van
dau van » dam van, dau va, cau van
va phan » van phan, va phat, va phap
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
mang xa » lang xa, mang may, dang xay
su tien » su kien, su hien, tu tieng
vi su » va su, ve su, ki su

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((mang xa) or (nang ma)) hoi. hieu va phan ((dau van) OR (dao van)) hanh vi su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((mang xa) OR (nang ma)) hoi. hieu va phan ((dau van) OR (dao van)) hanh vi su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((mang xa) or (nang ma)) hoi. hieu va phan ((dau van) OR (dao van)) hanh vi su tien".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((mang xa) or (nang ma)) hoi. hieu va phan ((dau van) OR (dao van)) hanh vi su tien*.