Perhaps you should try some spelling variations:
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
ve triet » va trien, su triet
tu sach » thu sach, su sach, te sach
ky lang » ky nang, ky tang, tay lang
ky dang » ky nang, ky danh
hanh ve » hanh vi, hanh va, hanh kem
le nam » he nam, le na, te nam
ve ve » de ve, va ve, ke ve

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) OR (ky dang)) hoa hoc. hieu ((le nam) or (ly nam)) thuc van hanh ve ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky dang)) hoa hoc. hieu ((le nam) OR (ly nam)) thuc van hanh ve ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky lang) OR (ky dang)) hoa hoc. hieu ((le nam) or (ly nam)) thuc van hanh ve ve triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) OR (ky dang)) hoa hoc. hieu ((le nam) or (ly nam)) thuc van hanh ve ve triet*.