Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
kinh va » kinh van, tinh va, sinh va
va kinh » va tinh, qua kinh
cuu tre » cua tre, cau tren, cau treo
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
luc va » duc va, tuc va, loc va
va cuu » va cau, va chu, va huu
va cao » va co, va dao, va bao

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 ((ty nang) or (ty hang)) xa hoi. lieu ((va cao) OR (va cac)) luc va kinh va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ((ty nang) OR (ty hang)) xa hoi. lieu ((va cao) OR (va cac)) luc va kinh va cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ((ty nang) or (ty hang)) xa hoi. lieu ((va cao) OR (va cac)) luc va kinh va cuu tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach ((ty nang) or (ty hang)) xa hoi. lieu ((va cao) OR (va cac)) luc va kinh va cuu tre*.