Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thue van » thue va, thuc van, thuy van
van hanh » van thanh, ban hanh, van anh
sach yu » sach y, sach tu, sach uu
yu hang » yu zhang, yu pang, yu wang
hang ca » hang va, nang cao, hang tai
hieu va » lieu va
ca thue » ca thu, ca hue, cuc thue
ca hoi » cau hoi, cua hoi, xa hoi
vi cua » vai cua, di cua
cua te » cua tu

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 yu hang ca hoi. ((hieu va) or (hieu qua)) ca thue van hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach yu hang ca hoi. ((hieu va) OR (hieu qua)) ca thue van hanh vi cua te.
• Adding a wildcard symbol may retrieve word variants: toc sach yu hang ca hoi. ((hieu va) or (hieu qua)) ca thue van hanh vi cua te*.