Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
van tham » van thanh, van tuan, van chat
thuc dan » thuc hanh, hoc dan, thuc vat
cua viet » ca viet, hoa viet, cua vat
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
va tham » va cham, va thanh, va thuat
thuc va » thuc vat, thuc day
vi cua » vai cua, di cua

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 nang ma hoa. hieu ((va tham) OR (van tham)) ((thuc va) or (thuc dan)) hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ma hoa. hieu ((va tham) OR (van tham)) ((thuc va) OR (thuc dan)) hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ma hoa. hieu ((va tham) OR (van tham)) ((thuc va) or (thuc dan)) hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ma hoa. hieu ((va tham) OR (van tham)) ((thuc va) or (thuc dan)) hanh vi cua viet*.