Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cao hoi » cau hoi, co hoi, cao hoc
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam
xuc va » duc va, tuc va, xac va
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua
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)) ky nang cao hoi. hieu ve cam ((xuc va) OR (luc va)) hanh vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang cao hoi. hieu ve cam ((xuc va) OR (luc va)) hanh vi cua tu*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky nang cao hoi. hieu ve cam ((xuc va) OR (luc va)) hanh vi cua tu*".