Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, pham duy
hanh dai » hanh tai, hanh dao, vanh dai
sach thu » sach thue, sach thieu, sach tham
duc tang » duc thang, duc tan, tuc tang
van dai » vanh dai, van dao, van hai
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
sach ty » sach y, sach tu, xach tay
nang xa » nang x, lang xa, nang ma
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ty) or (sach thu)) nang xa hoi. hieu ve cham duc tang ((hanh dai) or (van dai)) va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thu)) nang xa hoi. hieu ve cham duc tang ((hanh dai) OR (van dai)) va thiet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach thu)) nang xa hoi. hieu ve cham duc tang ((hanh dai) or (van dai)) va thiet*.