Perhaps you should try some spelling variations:
tu tuong » tu dong
nang mai » nang ma, nang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
duc van » duc va, duc tan, duc manh
su viet » so viet
hanh ki » hanh vi, hanh ky, hanh kien
tu sach » thu sach, su sach, te sach
sach vu » sach va, sach tu, sach uu
hieu va » lieu va, hieu qua
vu nang » vuc nang, va nang, vu dang
luc van » luoc van, luu van, luc va
va cam » va cham, va cac, va cao

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 vu nang mai khoi. hieu va cam ((luc van) or (duc van)) hanh ki ((su viet) or (tu tuong))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vu nang mai khoi. hieu va cam ((luc van) OR (duc van)) hanh ki ((su viet) OR (tu tuong)).
• Adding a wildcard symbol may retrieve word variants: tu sach vu nang mai khoi. hieu va cam ((luc van) or (duc van)) hanh ki ((su viet) or (tu tuong))*.