Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
su triet » su viet, su tien, ve triet
dang mat » dang mau, dung mat, dang hat
van hanh » van thanh, ban hanh, van ban
dang vat » dang van, dong vat, dang nhat
va tham » van tham, va cham, va thanh
van anh » van thanh, tuan anh, van minh
tu sach » thu sach, su sach, te sach
sach vu » sach va, sach tu, sach uu
hieu va » lieu va, hieu qua
ki su » ky su

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 vu ((dang mat) or (dang vat)) hoi. hieu va tham thuc ((van hanh) or (van anh)) ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vu ((dang mat) OR (dang vat)) hoi. hieu va tham thuc ((van hanh) OR (van anh)) ki su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach vu ((dang mat) or (dang vat)) hoi. hieu va tham thuc ((van hanh) or (van anh)) ki su triet*.