Perhaps you should try some spelling variations:
trinh dan » trinh han, trinh san, trinh da
su triet » su viet, su tien, ve triet
tu quynh » thu quynh, thuy quynh, truc quynh
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
ty nang » ky nang, ty xang, ty hang
ve nam » he nam, va nam, le nam
tu quy » tu duy
nang o » nang co, nang ho, nang ro
dan su » dang su
o hoi » co hoi, o hoc, o hai

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 ty nang o hoi. hieu ve nam ((tu quy) or (tu quynh)) trinh dan su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang o hoi. hieu ve nam ((tu quy) OR (tu quynh)) trinh dan su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang o hoi. hieu ve nam ((tu quy) or (tu quynh)) trinh dan su triet*.