Perhaps you should try some spelling variations:
dinh cuu » dinh chi
vu sach » vu bach, su sach, vu khach
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, va danh
y lang » o lang, tay lang, yen lang
_ lang » o lang, _ land
va cam » va cham, va cac, va cao
vi cuu » vi luu, vinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ((y lang) OR (_ lang)) xa hoi. hieu va cam duc va hanh ((vi cuu) or (dinh cuu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ((y lang) OR (_ lang)) xa hoi. hieu va cam duc va hanh ((vi cuu) OR (dinh cuu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ((y lang) OR (_ lang)) xa hoi. hieu va cam duc va hanh ((vi cuu) or (dinh cuu)) tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ((y lang) OR (_ lang)) xa hoi. hieu va cam duc va hanh ((vi cuu) or (dinh cuu)) tre*.