Perhaps you should try some spelling variations:
"nhung thi luan van. thoi nguyen vu hai" » "nhung thi luan van. thai nguyen vu hai", "nhung thi luan van. thi nguyen vu hai", "nhung thi luan van. tuoi nguyen vu hai", "phung thi luan van. thoi nguyen vu hai", "nhung tri luan van. thoi nguyen vu hai", "nhung chi luan van. thoi nguyen vu hai", "nhung thi luan van. thoi nguyen tu hai", "nhung thi luan van. thoi nguyen van hai", "nhung thi luan van. thoi nguyen duc hai", "nhung thi lan van. thoi nguyen vu hai", "nhung thi xuan van. thoi nguyen vu hai", "nhung thi loan van. thoi nguyen vu hai", "nhung thi luan van. thoi nguyen su hai", "nhung thi luan van. thoi nguyen vu ha"
"nhung thoi que van. thi yen truc may" » "phung thi que van. thi yen truc may", "nhung loi que van. thi yen truc may", "nhung tri que van. thi yen truc may", "nhung thoi quen van. thi yen truc may", "nhung thon que van. thi yen truc may", "nhung thong que van. thi yen truc may", "nhung thoi que van. thi kien truc may", "nhung thoi que van. thi yen tu may", "nhung thoi que van. thi yen tren may", "nhung thoi que van. thi yen truc va", "nhung thoi qua van. thi yen truc may", "nhung thoi quy van. thi yen truc may", "nhung thoi quyet van. thi yen truc may"

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("nhung thoi que van. thi yen truc may") OR ("nhung thi luan van. thoi nguyen vu hai"))~.
• Removing quotes may allow a broader search: (( nhung thoi que van. thi yen truc may ) or ( nhung thi luan van. thoi nguyen vu hai ))~.
• Adding a wildcard symbol may retrieve word variants: (("nhung thoi que van. thi yen truc may") or ("nhung thi luan van. thoi nguyen vu hai"))*.