Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
cau tren » cu tren, dau tren, ca tren
thuc ca » thuc cua, thuc can, thuc cao
ve pham » vi pham, v pham, ve phan
hieu ve » hieu va, hieu van
tu sach » thu sach, te sach, vu sach
su sach » so sach, vu sach
tu cach » tu cac
cao hoi » cau hoi, co hoi, cao hoc
ca dan » cac dan, ca dao
ca cau » cua cau, cac cau, can cau

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) or (tu cach))) or (su sach)) ky nang cao hoi. hieu ve pham thuc ca dan ca cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((tu sach) OR (tu cach))) OR (su sach)) ky nang cao hoi. hieu ve pham thuc ca dan ca cau tren.
• Adding a wildcard symbol may retrieve word variants: ((((tu sach) or (tu cach))) or (su sach)) ky nang cao hoi. hieu ve pham thuc ca dan ca cau tren*.