Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
ve triet » va trien, su triet
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
thuc va » thuc dan, thuc day
hang di » hang doi, hang vi, hang dien
di ve » dai ve, de ve, do ve

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang mai hoi. hieu va cac ((thuc vat) OR (thuc va)) hang di ve triet~.
• Adding a wildcard symbol may retrieve word variants: su sach ty nang mai hoi. hieu va cac ((thuc vat) or (thuc va)) hang di ve triet*.