Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
thi cong » tai cong, thien cong
hanh tai » thanh tai, hang tai, han tai
thi nang » ki nang, thi hanh
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
ca hoi » cau hoi, cua hoi, xa hoi
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, tuc xa
tai su » tai so, tai tu, lai 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 ((thi nang) OR (thi cong)) ca hoi. hieu va cam tuc va hanh tai su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((thi nang) OR (thi cong)) ca hoi. hieu va cam tuc va hanh tai su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((thi nang) OR (thi cong)) ca hoi. hieu va cam tuc va hanh tai su triet*.