Perhaps you should try some spelling variations:
van chat » cao chat
thu sach » tu sach, thuat sach, thuoc sach
tang ho » tang cho, tung ho, tang ha
sach ky » sac ky, sach y, sach ty
nang ho » nang hoc, nang co, nang cao
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac
cac su » cach su, cac sau, cac du
va tao » va bao, va cao, va tac
va cau » van cau, va cac, va dau
su va » su van, tu va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((nang ho) or (tang ho)) hoi. hieu ve cac su va tao ((va cau) or (van chat)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang ho) OR (tang ho)) hoi. hieu ve cac su va tao ((va cau) OR (van chat)) tren.
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang ho) or (tang ho)) hoi. hieu ve cac su va tao ((va cau) or (van chat)) tren*.