Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
cham truc » cau truc, pham thuc, nam truc
su triet » su viet, su tien, ve triet
hang dai » hoang dai, hang tai, hang dau
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
sach ly » sach lo, sach ty, sach hay
hieu vu » hieu va, hieu ve, hieu su
dai tai » dai hai, dai thao
di su » doi su, ki su, da su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ly) or (sach y)) hang dai tai. hieu vu ((cham truc) OR (nham thuc)) va hanh di su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ly) OR (sach y)) hang dai tai. hieu vu ((cham truc) OR (nham thuc)) va hanh di su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ly) or (sach y)) hang dai tai. hieu vu ((cham truc) OR (nham thuc)) va hanh di su triet".
• Adding a wildcard symbol may retrieve word variants: su ((sach ly) or (sach y)) hang dai tai. hieu vu ((cham truc) OR (nham thuc)) va hanh di su triet*.