Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
nang mai » nang ma, nang tai, lang mai
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
va thanh » gia thanh, va tinh, le thanh
bo sach » co sach, hoc sach
mai hoi » mai khoi, dai hoi, lai hoi
nam luc » nang luc, nhan luc, nam duoc
cac cua » cach cua, cac qua, ca cua
sach ky » sac ky, sach y, sach ty
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach ky nang mai hoi. hieu van ((nam luc) or (nam thuc)) ((va thanh) OR (ban thanh)) cac cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach ky nang mai hoi. hieu van ((nam luc) OR (nam thuc)) ((va thanh) OR (ban thanh)) cac cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "bo sach ky nang mai hoi. hieu van ((nam luc) or (nam thuc)) ((va thanh) OR (ban thanh)) cac cua te".
• Adding a wildcard symbol may retrieve word variants: bo sach ky nang mai hoi. hieu van ((nam luc) or (nam thuc)) ((va thanh) OR (ban thanh)) cac cua te*.