Perhaps you should try some spelling variations:
vien dao » vien da, vien cao, bien dao
nang mai » nang tai, lang mai, nang cai
trinh di » trinh do, trinh dien, trinh dinh
va trinh » van trinh, va tinh, lap trinh
vien dai » hien dai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, tuc xa
di cua » dai cua, doi cua, de cua

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 ky ((nang mai) or (nang ma)) hoi. hieu ((vien dao) OR (vien dai)) tuc va trinh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang mai) OR (nang ma)) hoi. hieu ((vien dao) OR (vien dai)) tuc va trinh di cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang mai) or (nang ma)) hoi. hieu ((vien dao) OR (vien dai)) tuc va trinh di cua tre*".