Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
thu hang » thi hang, thuc hanh, thu huong
thu nang » thi nang, thu bang, tho nang
cho hoc » co hoc, khoa hoc
hieu ve » hieu va, hieu van
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh
cua cau » cua cac, cua chu, cua cay
ve cac » va cac, vien cac
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: doc sach ((thu nang) OR (thu hang)) cho hoc. hieu ve cac ((xuc van) or (duc van)) hanh vi cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ((thu nang) OR (thu hang)) cho hoc. hieu ve cac ((xuc van) OR (duc van)) hanh vi cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ((thu nang) OR (thu hang)) cho hoc. hieu ve cac ((xuc van) or (duc van)) hanh vi cua cau*".