Perhaps you should try some spelling variations:
hieu quan » lieu quan, thien quan, lien quan
hoc sach » hoc sinh, hoc cac, hoc anh
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
hanh di » hanh vi, hanh de, hang di
duc van » duc va, duc tan, duc manh
cam duc » cam xuc, cao duc, pham duc
cau tre » cau tren, cau treo, cau tra
nang xa » nang x, lang xa, nang ma
ly nang » ky nang, ly hang, ly vang
di cau » da cau, diem cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (hoc sach)) ly nang xa hoi. ((hieu quan) or (hieu qua)) cam duc van hanh di cau tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (hoc sach)) ly nang xa hoi. ((hieu quan) OR (hieu qua)) cam duc van hanh di cau tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (hoc sach)) ly nang xa hoi. ((hieu quan) or (hieu qua)) cam duc van hanh di cau tre*.