Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
nang mai » nang ma, nang tai, lang mai
hien cac » thien cac, vien cac, hieu cac
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
mai hoi » mai khoi, dai hoi, lai hoi
dac van » cac van, dam van, duc van
dao van » do van, dang van
vi cua » vai cua, di 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 ty nang mai hoi. hieu hien cac ((dac van) OR (dao van)) hanh vi cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang mai hoi. hieu hien cac ((dac van) OR (dao van)) hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang mai hoi. hieu hien cac ((dac van) OR (dao van)) hanh vi cua viet*.