Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu van » thien van, lieu va, hieu ve
van hanh » van thanh, ban hanh, van anh
hanh di » hanh vi, hanh de, hang di
luc van » luoc van, luu van, duc van
cam luc » cam xuc, cau luc
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
mang xa » mang may, dang xay, mang cua
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ky ((mang xa) or (lang xa)) hoi. ((hieu va) or (hieu van)) cam luc van hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky ((mang xa) OR (lang xa)) hoi. ((hieu va) OR (hieu van)) cam luc van hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: thuat sach ky ((mang xa) or (lang xa)) hoi. ((hieu va) or (hieu van)) cam luc van hanh di cua tre*.