Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thu nang » thi nang, thu hang, thu bang
duy van » duy vat, dung van
hieu ve » hieu va, hieu van
cua cau » cua cac, cua chu, cua cay
nang co » nang cao, nang doc, nang noi
ve cac » va cac, vien cac
vu van » tu van
vi cua » vai cua, di cua

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)) thu nang co hoc. hieu ve cac ((vu van) or (duy van)) hanh vi cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) thu nang co hoc. hieu ve cac ((vu van) OR (duy van)) hanh vi cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) thu nang co hoc. hieu ve cac ((vu van) or (duy van)) hanh vi cua cau*".