Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cham tuc » nham thuc, pham thuc, cham soc
hanh doi » thanh doi, hanh noi, hang doi
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
ca tren » cau tren, cu tren, la tren
doi ca » doi cua, doi cay, duoi ca
5 hoi » o hoi

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

• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang ((5 hoi) OR (x ho)). hieu qua ((cham tuc) OR (tham thuc)) va hanh doi ca tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang ((5 hoi) or (x ho)). hieu qua ((cham tuc) OR (tham thuc)) va hanh doi ca tren~".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang ((5 hoi) or (x ho)). hieu qua ((cham tuc) OR (tham thuc)) va hanh doi ca tren*.