Perhaps you should try some spelling variations:
hoc sac » hoc sach, hoc cac, hoc mac
nang xa » nang x, lang xa, nang ma
ca tren » cau tren, cu tren, la tren
sac ky » cac ky, sai ky
ve cau » ke cau, ve cac, le cau
va cau » van cau, va cac, va dau
vu dao » va dao, vu cao, ve dao
dao va » dao van, tao va, do va
va ca » va cac, va cao, va cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sac ky nang xa hoi. hieu ((ve cau) OR (va cau)) phuc vu dao va ca tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sac ky nang xa hoi. hieu ((ve cau) OR (va cau)) phuc vu dao va ca tren".
• Adding a wildcard symbol may retrieve word variants: hoc sac ky nang xa hoi. hieu ((ve cau) OR (va cau)) phuc vu dao va ca tren*.