Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
quoc ban » quoc bao, quoc lan, quoc quan
ve cham » va cham, ve chat, vu cham
hoc bao » hoc cao, hoc bai, hoc bo
hanh tu » anh tu, danh tu
sach ty » sach y, sach tu, sach thu
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
tu cua » hu cua, vu cua
sac ky » cac ky, sai ky
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: tu ((sac ky) or (sach ty)) nang mai hoi. hieu ve cham ((quoc ban) or (hoc bao)) hanh tu cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sac ky) OR (sach ty)) nang mai hoi. hieu ve cham ((quoc ban) OR (hoc bao)) hanh tu cua tu.
• Adding a wildcard symbol may retrieve word variants: tu ((sac ky) or (sach ty)) nang mai hoi. hieu ve cham ((quoc ban) or (hoc bao)) hanh tu cua tu*.