Today, this specific 1972 edition is highly sought after by collectors and serious polyglots because it is now out of print.
You're interested in learning more about the language learning method called "Assimil" and specifically about the 1972 PDF version of "Le serbo-croate sans peine" (which translates to "Serbo-Croatian without pain"). Assimil - Le serbo-croate sans peine -1972- PDF...
: A guide tailored for French speakers to master the tricky Slavic consonants like č , ć , đ , and dž . Today, this specific 1972 edition is highly sought