Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
cham tuc » nham thuc, tham thuc, cham soc
nang tai » hang tai, tang tai, sang tai
hieu van » hieu va, thien van, hieu ve
danh vai » danh sai, danh va, doanh van
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, va hanh
su sach » so sach, vu sach
tai hoi » tai khoi, dai hoi, tai hai
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang

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 tai hoi. ((hieu van) OR (lieu va)) ((cham tuc) or (pham thuc)) va danh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang tai hoi. ((hieu van) OR (lieu va)) ((cham tuc) OR (pham thuc)) va danh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang tai hoi. ((hieu van) OR (lieu va)) ((cham tuc) or (pham thuc)) va danh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach y nang tai hoi. ((hieu van) OR (lieu va)) ((cham tuc) or (pham thuc)) va danh vai cua tre*.