Perhaps you should try some spelling variations:
toan hanh » toan thanh, toan anh, tran hanh
toc sach » hoc sach, doc sach, thuoc sach
nang cho » nang chon, ngang cho, sang cho
tan hanh » tan thanh, tang hanh, tran hanh
sach tu » sach thu, cach tu, sach ty
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
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: toc sach tu ((nang cho) or (nang cao)) hoc. hieu ve cac duc ((tan hanh) OR (toan hanh)) vi cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tu ((nang cho) OR (nang cao)) hoc. hieu ve cac duc ((tan hanh) OR (toan hanh)) vi cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach tu ((nang cho) or (nang cao)) hoc. hieu ve cac duc ((tan hanh) OR (toan hanh)) vi cua cau*".