Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc anh
lang mai » lang dai, lang hai, lang man
mai khoi » mai khoa, tai khoa, cac khoi
hieu va » lieu va, hieu qua
tai cuu » tai cuc, tai buu, tai cua
han tai » hang tai, nhan tai, van tai
van han » van hanh, van phan, van nhan
xuc van » duc van, luc van, vuc van
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu van
ky lang » ky nang, ky dang, ky tang
hoc cac » hoc cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc sach) or (hoc cac)) ky lang mai khoi. ((hieu ve) OR (hieu va)) cam xuc van han tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (hoc cac)) ky lang mai khoi. ((hieu ve) OR (hieu va)) cam xuc van han tai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) or (hoc cac)) ky lang mai khoi. ((hieu ve) OR (hieu va)) cam xuc van han tai cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (hoc cac)) ky lang mai khoi. ((hieu ve) OR (hieu va)) cam xuc van han tai cuu tre*.