Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
dua tren » dung tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet

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 ky nang mai khoi. hieu va cac nuoc va hanh vi ((dua tren) or (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang mai khoi. hieu va cac nuoc va hanh vi ((dua tren) OR (cua tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang mai khoi. hieu va cac nuoc va hanh vi ((dua tren) or (cua tre))*.