Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
toc sach » hoc sach, doc sach, thuoc sach
vien cac » vien bach, vien dai, vien da
duc van » duc va, duc tan, duc manh
xuc van » luc van, vuc van, xuc ban
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, ma hoa
vi cua » vai cua, di cua
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: ((te sach) or (toc sach)) ty nang ma hoi. hieu vien cac ((xuc van) or (duc van)) hanh vi cua cu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty nang ma hoi. hieu vien cac ((xuc van) OR (duc van)) hanh vi cua cu.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ty nang ma hoi. hieu vien cac ((xuc van) or (duc van)) hanh vi cua cu*.