Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
xay hoi » xa hoi, cay phoi, gay thoi
tay hoi » tay ho, tao hoi, tay thai
thi van » thi lan, thi hanh, thi nang
nam sua » nam cua, nam suu, nam mua
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
sach o » sach lo, sac o, sach y
o dang » xo dang, do dang, so dang
sua va » suat va, vua va, xua va
vi su » va su, ve su, ki 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 o dang ((xay hoi) or (tay hoi)). thi van nam sua va danh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach o dang ((xay hoi) OR (tay hoi)). thi van nam sua va danh vi su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach o dang ((xay hoi) or (tay hoi)). thi van nam sua va danh vi su triet*.