Perhaps you should try some spelling variations:
nghien thu » nghiem thuc, nghiep thuc, nghien cuu
co hoang » do hoang, cam hoang, cap hoang
toc cac » hoc cac, tuc cac, ton cac
cac thu » cach thuc, cac thoi
thu vat » thuc vat, thu va, thuat vat
co hang » cho hang, co chang, co bang
nhan va » nhan tai, nhan dan, nhan tao
hoc xa » hoc ma
hoi ca » hoi cua, hoi cac, hoi cau

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "toc cac thu vat, nghien thu cong ((co hang) OR (co hoang)) hoa hoc xa hoi ca nhan va~".
• Adding a wildcard symbol may retrieve word variants: toc cac thu vat, nghien thu cong ((co hang) OR (co hoang)) hoa hoc xa hoi ca nhan va*.