Perhaps you should try some spelling variations:
hieu thien » hieu hien, chieu chien, dieu khien
thien hach » thien thanh, hien hanh
hach xuc » thach duc, hanh xu, cach xu
va trinh » van trinh, va tinh, lap trinh
van phan » van phong, van thanh, luan phan
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
xuc va » duc va, tuc va, luc va
x hoi » xa hoi, o hoi, x ho
luan » quan, lan

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 x hoi. hieu thien hach xuc va trinh ((van phan) or (luan van)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu thien hach xuc va trinh ((van phan) OR (luan van)) tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu thien hach xuc va trinh ((van phan) or (luan van)) tre*.