Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
pham thuc » phap thuc, pham chuc, nham thuc
thu sach » tu sach, thuat sach, thu hoach
day hang » dat hang, dai hang, day nang
thuc day » thuc dan, thuc vat
hang di » hang doi, hang vi, hang dien
ve pham » vi pham, v pham, ve phan
hieu ve » hieu va, hieu van
cao hoc » co hoc, cho hoc, chat hoc
tao hoi » tao khoi, tao boi, tay hoi
y nang » ky nang, ly nang, v nang
di cua » dai cua, doi cua, de cua
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: ((thu sach) OR (thuoc sach)) y nang ((tao hoi) or (cao hoc)). hieu ve pham thuc day hang di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) y nang ((tao hoi) OR (cao hoc)). hieu ve pham thuc day hang di cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (thuoc sach)) y nang ((tao hoi) or (cao hoc)). hieu ve pham thuc day hang di cua te".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (thuoc sach)) y nang ((tao hoi) or (cao hoc)). hieu ve pham thuc day hang di cua te*.