Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
bang hai » hang hai, dang hai, lang hai
hai cua » thai cua, dai cua, hoi cua
duc ban » duc van, dua ban, duc man
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
va cam » va cham, va cac, va cao
cua tu » cua tuc, cua su, cua cu

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 ty ((nang x) or (nang ma)) hoi. hieu va cam ((duc ban) or (duc tan)) bang hai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty ((nang x) OR (nang ma)) hoi. hieu va cam ((duc ban) OR (duc tan)) bang hai cua tu.
• Adding a wildcard symbol may retrieve word variants: thu sach ty ((nang x) or (nang ma)) hoi. hieu va cam ((duc ban) or (duc tan)) bang hai cua tu*.