Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
toc sach » hoc sach, doc sach, thuoc sach
thanh vi » hanh vi, thanh va, thanh ve
hanh cho » danh cho, hang cho, han cho
cac duc » cac du, cao duc, cac dac
cua cau » cua cac, cua chu, cua can
duc van » duc va, duc tan, duc manh
hieu va » lieu va, hieu qua
cho hoc » co hoc, khoa hoc
ly hanh » ly anh, ly hang, lu hanh
cua cay » cua cac

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) OR (toc sach)) ly hanh cho hoc. hieu va cac duc van thanh vi ((cua cau) or (cua cay))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ly hanh cho hoc. hieu va cac duc van thanh vi ((cua cau) OR (cua cay))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ly hanh cho hoc. hieu va cac duc van thanh vi ((cua cau) or (cua cay))*".