Perhaps you should try some spelling variations:
vat hanh » vat thanh, van hanh, va hanh
hanh hai » thanh hai, nhanh hai, hang hai
va triet » va thiet, va trien, ve triet
sach ky » sach y, sach ty, sach kem
sac ky » cac ky, sai ky
le nam » ly nam, he nam, te nam
hai va » hai van, thai va, hoi va
x hoi » xa hoi, o hoi, x ho
le na » le va, le ta, le ha

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) nang x hoi. hieu ((le nam) OR (le na)) thuc vat hanh hai va triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sac ky)) nang x hoi. hieu ((le nam) or (le na)) thuc vat hanh hai va triet~".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sac ky)) nang x hoi. hieu ((le nam) or (le na)) thuc vat hanh hai va triet*.