Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
huong doi » huong dan, trong doi, dung doi
dan huong » dan phuong, doan huong, ban huong
thuc dan » thuc hanh, hoc dan, thuc vat
cau tren » cu tren, dau tren, ca tren
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
cuu tre » cua tre, cau treo
su sach » so sach, vu sach
y nang » ky nang, ly nang, v nang
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang ((x hoi) or (o hoi)). hieu ve pham thuc dan huong doi ((cuu tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ((x hoi) OR (o hoi)). hieu ve pham thuc dan huong doi ((cuu tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((x hoi) or (o hoi)). hieu ve pham thuc dan huong doi ((cuu tre) or (cau tren))*.