Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu va » lieu va, hieu qua
duc van » duc va, duc tan, duc manh
vuc van » luc van, thuc van, chuc van
te sach » toc sach
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, ma hoa
anh vi » hanh vi, anh va, anh ve
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 (thuoc sach)) ty nang ma hoi. hieu va cac ((vuc van) OR (duc van)) anh vi cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (thuoc sach)) ty nang ma hoi. hieu va cac ((vuc van) OR (duc van)) anh vi cua su.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (thuoc sach)) ty nang ma hoi. hieu va cac ((vuc van) OR (duc van)) anh vi cua su".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (thuoc sach)) ty nang ma hoi. hieu va cac ((vuc van) OR (duc van)) anh vi cua su*.