- 2851
- 1980-04-23
education: البحث العلمي
- 2845
- 1980-04-17
- 2843
- 1980-04-15
- 2840
- 1980-04-12
- 2839
- 1980-04-11
- 2838
- 1980-04-10
- 2836
- 1980-04-08
- 2835
- 1980-04-07
- 2831
- 1980-04-03
- 2829
- 1980-04-01
- 2817
- 1980-03-20
- 2816
- 1980-03-19
- 2802
- 1980-03-05
- 4589
- 1980-02-21
- 2784
- 1980-02-16
- 2775
- 1980-02-07
- 2752
- 1980-01-14
- 2751
- 1980-01-13
- 3018
- 1980-01-08
- 2733
- 1979-12-25