Perhaps you should try some spelling variations:
van nhanh » van thanh, van hanh, van khanh
nhanh hai » nhanh thai, thanh hai, nhanh ha
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
lo nang » ho nang, ly nang, loai nang
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
duc van » duc va, duc tan, duc manh
cua tu » cua tuc, cua cu, cua te
cua su » qua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (su sach)) lo nang x ho. hieu va cac duc van nhanh hai ((cua tu) OR (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) lo nang x ho. hieu va cac duc van nhanh hai ((cua tu) OR (cua su)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) lo nang x ho. hieu va cac duc van nhanh hai ((cua tu) OR (cua su))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) lo nang x ho. hieu va cac duc van nhanh hai ((cua tu) OR (cua su))*.