Perhaps you should try some spelling variations:
sach hoi » sach doi, sach moi, cach thoi
hoc phan » hoc dan
phoi hoc » hoi hoc, phoi thuoc, hoa hoc
van tuan » van quan, van ban, anh tuan
tuan van » luan van, tran van, tan van
te sach » toc sach
hoi van » hoi va, hoi dan, hai van
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: te sach hoi dap, nghien cuu mo ((hoc phan) or (hoc pho)) phoi hoc xa hoi van tuan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach hoi dap, nghien cuu mo ((hoc phan) OR (hoc pho)) phoi hoc xa hoi van tuan van.
• Adding a wildcard symbol may retrieve word variants: te sach hoi dap, nghien cuu mo ((hoc phan) or (hoc pho)) phoi hoc xa hoi van tuan van*.