Perhaps you should try some spelling variations:
tan hanh » tan thanh, tang hanh, toan hanh
su sach » so sach
vu sach » vu bach, vu khach
ly nang » ky nang, ly hang, ly vang
hieu va » lieu va, hieu qua
va giao » van giao, va giai, va gia
vai cua » dai cua, lai cua, bai cua
hai cua » thai cua, dai cua, hoi cua
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: ((su sach) OR (vu sach)) ly nang x hoi. hieu va giao duc tan hanh ((vai cua) or (hai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ly nang x hoi. hieu va giao duc tan hanh ((vai cua) OR (hai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (vu sach)) ly nang x hoi. hieu va giao duc tan hanh ((vai cua) or (hai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (vu sach)) ly nang x hoi. hieu va giao duc tan hanh ((vai cua) or (hai cua)) tre*.