Perhaps you should try some spelling variations:
thieu nien » thien nhien
hieu vien » hieu hien, hieu viec, hieu tieng
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
xuc van » duc van, luc van, vuc van
ly nang » ky nang, ly hang, ly vang
nang ma » tang ma, sang ma, nang cao
hanh di » hanh vi, hanh de, hang di
cac xuc » cam xuc, cac nuoc, chat xuc
di cua » dai cua, doi cua, de cua
ma hoi » mai hoi, xa hoi, ma hoa
cua tu » cua tuc, cua su, cua cu

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)) ly nang ma hoi. ((hieu vien) OR (thieu nien)) cac xuc van hanh di cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ly nang ma hoi. ((hieu vien) OR (thieu nien)) cac xuc van hanh di cua tu*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ly nang ma hoi. ((hieu vien) OR (thieu nien)) cac xuc van hanh di cua tu*".