Perhaps you should try some spelling variations:
nghien cac » nghiep cach, nghien cuu, nghiep cay
moc hoang » ngoc hoang, duc hoang, hoc hang
hung van » phung van, nhung van, dung van
cac cong » cua cong
van hung » van dung, manh hung, van duong
khoa hoc » hoa hoc
sach hoc » cach hoc, sach hoi, mach hoc
hai van » thai van, ha van, hai tan
su sach » so sach, vu sach
oc hang » hoc hang, oc sang, hoc hanh
hoc xa » hoc ma
xa hai » xa thai, xua hai, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach hoc tap, nghien cac cong ((oc hang) OR (moc hoang)) khoa hoc xa hai van hung van~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach hoc tap, nghien cac cong ((oc hang) OR (moc hoang)) khoa hoc xa hai van hung van".
• Adding a wildcard symbol may retrieve word variants: su sach hoc tap, nghien cac cong ((oc hang) OR (moc hoang)) khoa hoc xa hai van hung van*.