Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
han thai » han tai, van thai, than thoai
ban thai » ban than, ban thi, ban tai
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
xuc va » duc va, tuc va, luc va

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 xa hoi. hieu van cam xuc va ((han thai) OR (ban thai)) va (thiet or thieu)~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang xa hoi. hieu van cam xuc va ((han thai) OR (ban thai)) va (thiet OR thieu).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang xa hoi. hieu van cam xuc va ((han thai) OR (ban thai)) va (thiet or thieu)".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang xa hoi. hieu van cam xuc va ((han thai) OR (ban thai)) va (thiet or thieu)*.