Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cao tren » ca tren, cau tren, co tren
sach ky » sac ky, sach y, sach ty
phuc va » phuc vu, thuc va, chuc va
ve cau » ke cau, ve cac, le cau
va cau » van cau, va cac, va dau
va dan » ca dan, va dao, va dau
ca cao » ca dao, cu cao, ca cac
x hoi » xa hoi, o hoi, x ho

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 ky nang x hoi. hieu ((ve cau) OR (va cau)) phuc va dan ca cao tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky nang x hoi. hieu ((ve cau) OR (va cau)) phuc va dan ca cao tren".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky nang x hoi. hieu ((ve cau) OR (va cau)) phuc va dan ca cao tren*.