Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
thu nang » thi nang, thu bang, tho nang
van hanh » van thanh, ban hanh, van anh
thu hang » thi hang, thuc hanh, thu huong
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
cac xuc » cam xuc, chat xuc, cac cuoc
hieu ve » hieu va, hieu van
cho hoc » co hoc, khoa hoc
cua cau » cua cac, cua chu, cua cay
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) or (cac nuoc)) 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) OR (cac nuoc)) 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) or (cac nuoc)) van hanh vi cua cau*".