Perhaps you should try some spelling variations:
trinh quoc » trinh quan, chinh quoc, trinh doc
trinh duoc » trinh doc, trinh duc, tranh duoc
may nguoi » tay nguoi, ma nguoi, lay nguoi
hanh hoc » thanh hoc, hinh hoc, anh hoc
tu trinh » tu tinh, tieu trinh, qua trinh
li nguoi » loi nguoi, le nguoi, ly nguoi
lu hanh » luu hanh, du hanh, ly hanh
hoc may » hoc ma
duoc li » duoc si, duoc ly, duoc lieu
quoc li » quoc lo, quoc gia, quoc hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( lu hanh hoc may nguoi ) or ((( tu trinh duoc li nguoi ) or ( tu trinh quoc li nguoi ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( lu hanh hoc may nguoi ) OR ((( tu trinh duoc li nguoi ) OR ( tu trinh quoc li nguoi )))).
• Adding a wildcard symbol may retrieve word variants: (( lu hanh hoc may nguoi ) or ((( tu trinh duoc li nguoi ) or ( tu trinh quoc li nguoi ))))*.