Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thuc dan » thuc hanh, hoc dan, thuc vat
dan hanh » dang hanh, dan khanh, dan thanh
hanh dao » lanh dao, thanh dat, thanh dam
su triet » su viet, su tien, ve triet
nang co » nang cao, nang doc, nang noi
van dam » van nam, van dau, van lam
dao su » dao suu, dan su, cao 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) or (toc sach)) ky nang co hoc. thien ((van dam) or (van dao)) thuc dan hanh dao su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang co hoc. thien ((van dam) OR (van dao)) thuc dan hanh dao su triet.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang co hoc. thien ((van dam) or (van dao)) thuc dan hanh dao su triet*.