Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
cham duc » pham duc, cham soc, pham duy
tu sach » thu sach, su sach, te sach
va danh » va dinh, va dan, dia danh
hai cuc » tai cuc, hai cua, thai cua
hai cuu » hai cua, hai chu, thai cua
va hanh » van hanh, va thanh, ban hanh
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty nang ma hoi. hieu van cham duc ((va hanh) or (va danh)) ((hai cuu) OR (hai cuc)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ma hoi. hieu van cham duc ((va hanh) OR (va danh)) ((hai cuu) OR (hai cuc)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ma hoi. hieu van cham duc ((va hanh) or (va danh)) ((hai cuu) OR (hai cuc)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ma hoi. hieu van cham duc ((va hanh) or (va danh)) ((hai cuu) OR (hai cuc)) tre*.