Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
danh doi » danh di, thanh doi, dung doi
doi cua » dai cua, hoi cua
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
nang co » nang cao, nang doc, nang noi
va cam » va cham, va cac, va cao
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
v nang » va nang, vu nang, van nang

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 (dac sac)) v nang co hoc. hieu va cam ((luc va) OR (tuc va)) danh doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (dac sac)) v nang co hoc. hieu va cam ((luc va) OR (tuc va)) danh doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) or (dac sac)) v nang co hoc. hieu va cam ((luc va) OR (tuc va)) danh doi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (dac sac)) v nang co hoc. hieu va cam ((luc va) OR (tuc va)) danh doi cua tre*.