@incollection{MEM_2022_51_a12,
     author = {Georgieva, Ivanka and Angelova, Zhorzheta},
     title = {Ideas on systemizing problems for solving a triangle in teaching mathematics},
     booktitle = {},
     series = {Mathematics and Education in Mathematics},
     pages = {153--171},
     year = {2022},
     volume = {51},
     language = {bg},
     url = {http://geodesic.mathdoc.fr/item/MEM_2022_51_a12/}
}