Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
toc sach » hoc sach, doc sach, thuoc sach
sach tru » sach truc, sach thu, sach tu
tru nang » tra nang, tri nang, truc nano
vien cac » vien bach, vien dai, vien da
hanh vai » hanh vi, hanh va, hanh tai
nang ma » tang ma, sang ma, nang cao
luc van » luoc van, luu van, duc van
duc ban » duc tan, duc van, dua ban
vai cua » dai cua, hai cua, lai cua
ma hoi » mai hoi, xa hoi, ma hoa
cua cu » cua chu, cua cau, cua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach tru nang ma hoi. hieu vien cac ((luc van) or (duc ban)) hanh vai cua cu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tru nang ma hoi. hieu vien cac ((luc van) OR (duc ban)) hanh vai cua cu.
• Adding a wildcard symbol may retrieve word variants: toc sach tru nang ma hoi. hieu vien cac ((luc van) or (duc ban)) hanh vai cua cu*.