Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
su triet » su viet, su tien, ve triet
thu van » thuc van, thuy van, chu van
sach ky » sac ky, sach y, sach ty
te sach » toc sach
hoa hoi » khoa hoi, hoa hoc, hoc hoi
hoa doi » hoa dai, hoc doi, xoa doi
ky lang » ky nang, ky dang, ky tang
hieu he » hieu ve, hiem he, hieu le
he nam » ha nam, nghe nam
tu van » tu va
vai su » va su, van su, 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: te sach ky lang ((hoa hoi) OR (hoa doi)). hieu he nam ((thu van) or (tu van)) thanh vai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky lang ((hoa hoi) OR (hoa doi)). hieu he nam ((thu van) OR (tu van)) thanh vai su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky lang ((hoa hoi) OR (hoa doi)). hieu he nam ((thu van) or (tu van)) thanh vai su triet".
• Adding a wildcard symbol may retrieve word variants: te sach ky lang ((hoa hoi) OR (hoa doi)). hieu he nam ((thu van) or (tu van)) thanh vai su triet*.