Perhaps you should try some spelling variations:
manh hanh » xanh hanh, danh thanh, minh thanh
hieu van » hieu va, thien van, hieu ve
cham duc » pham duc, cham soc, pham duy
duc manh » suc manh, duc anh, duc minh
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
loai ca » loai cay, loai cua, loai va
lai ca » lai cua, lai cam, bai ca
x hoi » xa hoi, o hoi, x ho

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 ty nang x hoi. ((hieu van) or (lieu va)) cham duc manh hanh ((lai ca) OR (loai ca)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang x hoi. ((hieu van) OR (lieu va)) cham duc manh hanh ((lai ca) OR (loai ca)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang x hoi. ((hieu van) or (lieu va)) cham duc manh hanh ((lai ca) OR (loai ca)) viet".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang x hoi. ((hieu van) or (lieu va)) cham duc manh hanh ((lai ca) OR (loai ca)) viet*.