Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, va tinh
ban hanh » ban hang
chat xuc » chat huu, cam xuc, chao xu
van chat » cao chat
cau tren » cu tren, dau tren, ca tren
cao hoi » cau hoi, co hoi, cao hoc
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
vi cau » va cau, ve cau, di cau

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) OR (sach ty)) nang cao hoi. hieu van chat xuc ((ban hanh) or (va thanh)) vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sach ty)) nang cao hoi. hieu van chat xuc ((ban hanh) OR (va thanh)) vi cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) OR (sach ty)) nang cao hoi. hieu van chat xuc ((ban hanh) or (va thanh)) vi cau tren".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) OR (sach ty)) nang cao hoi. hieu van chat xuc ((ban hanh) or (va thanh)) vi cau tren*.