Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
hanh doi » thanh doi, hanh noi, hang doi
van hanh » van thanh, ban hanh, van anh
nam thuc » nam thuoc, am thuc, nam thu
doi cua » dai cua, hoi cua
nam luc » nang luc, nhan luc, nam duoc
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
mang xa » mang may, dang xay, mang cua
cua te » cua tu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((mang xa) OR (lang xa)) hoi. hieu van ((nam luc) OR (nam thuc)) van hanh doi cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((mang xa) or (lang xa)) hoi. hieu van ((nam luc) OR (nam thuc)) van hanh doi cua te~".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((mang xa) or (lang xa)) hoi. hieu van ((nam luc) OR (nam thuc)) van hanh doi cua te*.