Perhaps you should try some spelling variations:
nghien cua » nghien cuu, nghiep cua, nghiep vua
khanh hoa » thanh hoa, hang hoa
thu sach » tu sach, thuat sach, thuoc sach
sach hoc » cach hoc, sach hoi, mach hoc
pham tan » pham tuan, pham van, pham tai
va pham » van pham, va phat, va phap
hoc xa » hoc ma

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach hoc tap, nghien cua ((van hoc) OR (van hoa)) khanh hoa hoc xa hoi va pham tan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach hoc tap, nghien cua ((van hoc) OR (van hoa)) khanh hoa hoc xa hoi va pham tan".
• Adding a wildcard symbol may retrieve word variants: thu sach hoc tap, nghien cua ((van hoc) OR (van hoa)) khanh hoa hoc xa hoi va pham tan*.