Perhaps you should try some spelling variations:
lang mai » lang dai, lang hai, lang man
ban hanh » ban hang
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach vu » sach va, sach tu, sach uu
lang ha » long ha
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
duc ban » duc tan, duc van, dua ban
hanh ki » hanh vi, hanh ky, hanh kien
ki su » ky su

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 ((lang mai) or (lang ha)) hoi. hieu va cac duc ban hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vu ((lang mai) OR (lang ha)) hoi. hieu va cac duc ban hanh ki su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach vu ((lang mai) or (lang ha)) hoi. hieu va cac duc ban hanh ki su triet*.