Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, pham thu
thien van » thi van
nham thuc » nhan thuc, nam thuc, nham thu
hieu van » hieu va, lieu va, hieu ve
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
co sach » bo sach, cuon sach, hoc sach
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
cu tren » tu tren, dua tren
x hoi » xa hoi, o hoi, x ho
va cu » va cau, va chu, va su

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

• Performing a fuzzy search may retrieve terms with similar spellings: co sach ly nang x hoi. ((hieu van) or (thien van)) ((pham thuc) OR (nham thuc)) va hanh va cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ly nang x hoi. ((hieu van) OR (thien van)) ((pham thuc) OR (nham thuc)) va hanh va cu tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ly nang x hoi. ((hieu van) or (thien van)) ((pham thuc) OR (nham thuc)) va hanh va cu tren".
• Adding a wildcard symbol may retrieve word variants: co sach ly nang x hoi. ((hieu van) or (thien van)) ((pham thuc) OR (nham thuc)) va hanh va cu tren*.