Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu va » lieu va, hieu qua
luc van » luoc van, luu van, duc van
xuc van » duc van, vuc van, xuc ban
te sach » toc sach
tang ma » mang may, tang van
ty tang » tay tang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cham, va cac, va cao
vi cua » vai cua, di cua
cua su » qua 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 (thuat sach)) ty tang ma hoi. hieu va cam ((xuc van) OR (luc van)) hanh vi cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (thuat sach)) ty tang ma hoi. hieu va cam ((xuc van) OR (luc van)) hanh vi cua su.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (thuat sach)) ty tang ma hoi. hieu va cam ((xuc van) OR (luc van)) hanh vi cua su".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (thuat sach)) ty tang ma hoi. hieu va cam ((xuc van) OR (luc van)) hanh vi cua su*.