Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nang mai » nang ma, nang tai, lang mai
dua ban » cua ban, qua ban, mua ban
hai cuc » hai cua, thai cua, hai huoc
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ty nang » ky nang, ty xang, ty hang
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ty nang mai hoi. hieu ve cam ((dua ban) or (dia ban)) thanh ((hai cuc) OR (tai cuc)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty nang mai hoi. hieu ve cam ((dua ban) OR (dia ban)) thanh ((hai cuc) OR (tai cuc)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty nang mai hoi. hieu ve cam ((dua ban) or (dia ban)) thanh ((hai cuc) OR (tai cuc)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ty nang mai hoi. hieu ve cam ((dua ban) or (dia ban)) thanh ((hai cuc) OR (tai cuc)) tre*.