Perhaps you should try some spelling variations:
lang khoan » hang khoa, dang khoa, lang kham
khoan hoi » khoan nhoi, khoa hoi, khoa hoc
su triet » su viet, su tien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
le nam » ly nam, le na, te nam
ve nam » va nam, te nam, viet nam
vai su » va su, van su, lai su
he nam » ha nam, nghe nam

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 lang khoan hoi. hieu ((((ve nam) or (he nam))) or (le nam)) thuc dan hanh vai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang khoan hoi. hieu ((((ve nam) OR (he nam))) OR (le nam)) thuc dan hanh vai su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang khoan hoi. hieu ((((ve nam) or (he nam))) or (le nam)) thuc dan hanh vai su triet*.