Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
van hanh » ban hanh, van anh, van ban
cham tuc » nham thuc, pham thuc, tham thuc
su sach » so sach, vu sach
va cham » va chat, va tham
tai cua » thai cua, tai cuc, tri cua
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
nang va » nang van, hang va, nang ma
nang ro » nang co, nang ho, nang ra
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: su sach ty ((nang ro) or (nang va)) hoi. hieu va cham tuc ((van hanh) OR (van thanh)) tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang ro) OR (nang va)) hoi. hieu va cham tuc ((van hanh) OR (van thanh)) tai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((nang ro) or (nang va)) hoi. hieu va cham tuc ((van hanh) OR (van thanh)) tai cua te".
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang ro) or (nang va)) hoi. hieu va cham tuc ((van hanh) OR (van thanh)) tai cua te*.