Perhaps you should try some spelling variations:
quoc quan » qua quan, luc quan, hoc quan
hanh thai » nhanh thai, hinh thai, hanh tai
cua triet » cua viet, su triet, va triet
duc manh » suc manh, duc anh, duc minh
thai cua » than cua, tai cuc, tri cua
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ho » nang hoc, nang co, tang ho
hieu ve » hieu va, hieu van
ho hai » hoc hai, pho hai, cho hai
ve cac » va cac, vien cac

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 ky nang ho hai. hieu ve cac ((quoc quan) or (duc manh)) hanh thai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ho hai. hieu ve cac ((quoc quan) OR (duc manh)) hanh thai cua triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ho hai. hieu ve cac ((quoc quan) or (duc manh)) hanh thai cua triet*.