Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thi hang » thi hanh, thi nang, thi hong
van cac » van hac, van cau, van bac
te sach » toc sach
ty hang » ly hang, ty xang, thu hang
cua tre » cua te, cuu tre, cua triet
do hoc » co hoc, do hoa, du hoc
bo van » vo van, do van, ho van
so van » su van, vo van
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((ty hang) OR (thi hang)) do hoc. hieu van cac ((bo van) or (so van)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ty hang) OR (thi hang)) do hoc. hieu van cac ((bo van) OR (so van)) hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ty hang) OR (thi hang)) do hoc. hieu van cac ((bo van) or (so van)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ((ty hang) OR (thi hang)) do hoc. hieu van cac ((bo van) or (so van)) hanh vi cua tre*.