Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh van » thanh van, khanh van, hanh va
hau tren » dau tren, cau tren, thai tren
sach ky » sac ky, sach y, sach ty
cao hoc » co hoc, cho hoc, chat hoc
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
thuc va » thuc vat, thuc dan, thuc day
van hau » van ha, van hai, van dau
luc va » duc va, tuc va, loc va

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 ky nang cao hoc. hieu ve cham ((thuc va) or (luc va)) hanh van hau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang cao hoc. hieu ve cham ((thuc va) OR (luc va)) hanh van hau tren.
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang cao hoc. hieu ve cham ((thuc va) or (luc va)) hanh van hau tren*.