Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nang tai » hang tai, tang tai, sang tai
nang mai » nang ma, lang mai, nang cai
sach ky » sac ky, sach ty, sach kem
van cau » van dau, van hau, van chat
truc va » thuc va, thuc vat, trung va
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc ((sach ky) or (sach y)) ((nang mai) OR (nang tai)) khoi. hieu van cau truc va hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc ((sach ky) OR (sach y)) ((nang mai) OR (nang tai)) khoi. hieu van cau truc va hanh vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc ((sach ky) or (sach y)) ((nang mai) OR (nang tai)) khoi. hieu van cau truc va hanh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: thuoc ((sach ky) or (sach y)) ((nang mai) OR (nang tai)) khoi. hieu van cau truc va hanh vi cuu tre*.