Perhaps you should try some spelling variations:
ngoc toan » ngoc tan, ngoc thanh, ngoc hoa
ngoc tuan » ngo xuan
gian lang » gian dan
cuu cong » cua cong, thu cong, cac cong
noi tap » toi tap, ngoai tap, noi tiep
va gian » va gianh, van gian, va giai
hoc xa » hoc ma
tu ha » tu hat, tu va, vu ha

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ha noi tap, nghien cuu cong ((ngoc toan) or (ngoc tuan)) hoa hoc xa hoi va gian lang~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ha noi tap, nghien cuu cong ((ngoc toan) OR (ngoc tuan)) hoa hoc xa hoi va gian lang.
• Adding a wildcard symbol may retrieve word variants: tu ha noi tap, nghien cuu cong ((ngoc toan) or (ngoc tuan)) hoa hoc xa hoi va gian lang*.