Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thanh hai » thanh phan, thanh hoa, thanh san
ban thanh » ban hanh, ban hang
toc sach » hoc sach, doc sach, nuoc sach
nang mai » nang ma, nang tai, lang mai
hai cuc » tai cuc, hai cua, thai cua
dua ban » dia ban, cua ban, qua ban
cuc tre » duc tre, cua tre, cuu tre
mai hoi » mai khoi, dai hoi, lai hoi
ty nang » ky nang, ty xang, ty hang
ve cac » va cac, vien cac
ve cam » ve cham, va cam, ve cai

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