Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc anh
cau phuc » cau truc, chau phu, huu phuc
cao tren » ca tren, cau tren, co tren
hoc cac » hoc cao
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
phuc va » phuc vu, thuc va, chuc va
ve cau » ke cau, va cau, ve cac
va dan » ca dan, va dao, va dau
dan va » doan va, dan ca, ban va
va cao » va cac, va co, va dao

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 ((nang xa) or (lang xa)) hoi. hieu ve cau phuc va dan va cao tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (hoc cac)) ky ((nang xa) OR (lang xa)) hoi. hieu ve cau phuc va dan va cao tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) OR (hoc cac)) ky ((nang xa) or (lang xa)) hoi. hieu ve cau phuc va dan va cao tren".
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) OR (hoc cac)) ky ((nang xa) or (lang xa)) hoi. hieu ve cau phuc va dan va cao tren*.