Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hanh dau » hang dau, danh dau, han dau
chat hoc » chat hoa, chat thom, cho hoc
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
sac ky » cac ky, sai ky
dau su » dau tu, dan 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: tu ((sac ky) or (sach ty)) nang xa hoi. hieu va ((chat hoc) or (cham soc)) va hanh dau su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sac ky) OR (sach ty)) nang xa hoi. hieu va ((chat hoc) OR (cham soc)) va hanh dau su triet.
• Adding a wildcard symbol may retrieve word variants: tu ((sac ky) or (sach ty)) nang xa hoi. hieu va ((chat hoc) or (cham soc)) va hanh dau su triet*.