Perhaps you should try some spelling variations:
ve triet » va trien, su triet
nang mai » nang ma, nang tai, lang mai
sach ty » sach tu, sach thu, xach tay
hang vi » hang va, hanh vi, hang di
thuc va » thuc dan, thuc day
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ve cam » ve cham, ve cac, va cam
vi ve » va ve, gi ve, ve 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) OR (sach y)) nang mai hoi. hieu ve cam ((thuc vat) OR (thuc va)) hang vi ve triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) OR (sach y)) nang mai hoi. hieu ve cam ((thuc vat) or (thuc va)) hang vi ve triet~".
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) OR (sach y)) nang mai hoi. hieu ve cam ((thuc vat) or (thuc va)) hang vi ve triet*.