Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
lang hoa » hang hoa, lang ha, nang hoa
nam thuc » nam thuoc, am thuc, nam thu
vat hanh » vat thanh, van hanh, nhat hanh
ve triet » su triet
va trien » va truyen, va thiet, va tuyen
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
va nam » van nam, ha nam, va nay

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky lang hoa hoc. hieu va nam thuc ((vat hanh) or (va hanh)) vi ((ve triet) OR (va trien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky lang hoa hoc. hieu va nam thuc ((vat hanh) OR (va hanh)) vi ((ve triet) OR (va trien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky lang hoa hoc. hieu va nam thuc ((vat hanh) or (va hanh)) vi ((ve triet) OR (va trien))".
• Adding a wildcard symbol may retrieve word variants: thu sach ky lang hoa hoc. hieu va nam thuc ((vat hanh) or (va hanh)) vi ((ve triet) OR (va trien))*.