Perhaps you should try some spelling variations:
doanh hoa » doanh khoa, doanh hoan, danh hoa
tuan phan » luan phan, toan phan, tuan pham
thu sach » thuat sach, thuoc sach, thu hoach
cuu tong » cuu cong, cuu tinh, huu tung
so doanh » so danh, su doanh, hoa doanh
thai van » thi van, thanh van, thai vung
van tuan » van quan, van ban, anh tuan
tu sach » su sach, te sach, tu cach
tong so » tuong so, thong so, tong son
ca thai » chat thai, hoa thai
hoc ca » hoc cao, hoc cua, hoc cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (thu sach)) hoc tap, nghien cuu tong so doanh hoa hoc ca thai van tuan phan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) hoc tap, nghien cuu tong so doanh hoa hoc ca thai van tuan phan".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) hoc tap, nghien cuu tong so doanh hoa hoc ca thai van tuan phan*.